Note: This page contains sample records for the topic satellite-based terrestrial communication from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Satellite based estimates of terrestrial water storage variations in Turkey  

NASA Astrophysics Data System (ADS)

In recent years, the Gravity Recovery and Climate Experiment (GRACE) has provided a new tool to study terrestrial water storage variations (TWS) at medium and large spatial scales, providing quantitative measures of TWS change. Linear trends in TWS variations in Turkey were estimated using GRACE observations for the period March 2003 to March 2009. GRACE showed a significant decrease in TWS in the southern part of the central Anatolian region up to a rate of 4 cm/year. The Global Land Data Assimilation System (GLDAS) model also captured this TWS decrease event but with underestimated trend values. The GLDAS model represents only a part of the total TWS variations, the sum of soil moisture (2 m column depth) and snow water equivalent, ignoring groundwater variations. Therefore, GLDAS model derived TWS variations were subtracted from GRACE derived TWS variations to estimate groundwater storage variations. Results revealed that decreasing trends of TWS observed by GRACE in the southern part of central Anatolia were largely explained by the decreasing trends of groundwater variations which were confirmed by the limited available well groundwater level data in the region.

Lenk, Onur

2013-07-01

2

Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production  

Microsoft Academic Search

Abstract Operational monitoring,of global terrestrial gross primary production (GPP) and net primary,production (NPP) is now,underway,using imagery,from the satellite-borne Moderate,Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling issues that must be addressed,to link ground measurements to the satellite-based carbon flux estimates. Here,

David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gowers; Al A. Kirschbaums; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsyy; Allison L. Dunnt; Beverly E. Law; John L. Campbell; Walter C. Oechelii; Hyo Jung Kwonii; Tilden P. Meyers; Eric E. Small; S Hirley A. Kurc; John A. Gamon

3

Network design consideration of a satellite-based mobile communications system  

NASA Astrophysics Data System (ADS)

Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

Yan, T.-Y.

4

Space and terrestrial communications in military crisis response  

Microsoft Academic Search

Current and near future space and terrestrial communication capabilities are examined for tactical connectivity. Defense Communications Systems (DCS) connectivity, and commercial communications. Efficient and effective communications in response to a crisis will depend on a mix of space- and terrestrial-based systems from both the military and civilian sectors. Space-based systems described include UHF military satellite communications operating on the Fleet

1988-01-01

5

Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring  

Microsoft Academic Search

Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling issues that must be addressed to link ground measurements to

P. T URNER; THOMAS K. M AEIRSPERGER; S TITH T. G OWER; A. K I R S C H B A U Mz; STEVE W. R UNNING; M AOSHENG; Z HAO; S TEVEN C. W OFSY; J OHN; L. C AMPBELL; H Y O J U N G K W O Nk; TILDEN P. M EYERS; A. K URC; J O H N A. G A M O N zz

2005-01-01

6

ATMOSPHERIC CHANNEL EFFECTS ON TERRESTRIAL FREE SPACE OPTICAL COMMUNICATION LINKS  

Microsoft Academic Search

This paper illustrates the challenges imposed by the atmospheric channel on the design of a terrestrial laser communication link. The power loss due to scattering effect is described using the Kim\\/Kruse scattering model while the effect and the penalty imposed by atmospheric turbulence is highlighted by considering the bit error rate (BER) of an On- Off Keying modulated link in

W. Popoola; Z. Ghassemlooy; M. S. Awan; E. Leitgeb

7

Recent climate and fire disturbance impacts on boreal and arctic ecosystem productivity estimated using a satellite-based terrestrial carbon flux model  

NASA Astrophysics Data System (ADS)

and changing fire regimes in the northern (?45°N) latitudes have consequences for land-atmosphere carbon feedbacks to climate change. A terrestrial carbon flux model integrating satellite Normalized Difference Vegetation Index and burned area records with global meteorology data was used to quantify daily vegetation gross primary productivity (GPP) and net ecosystem CO2 exchange (NEE) over a pan-boreal/Arctic domain and their sensitivity to climate variability, drought, and fire from 2000 to 2010. Model validation against regional tower carbon flux measurements showed overall good agreement for GPP (47 sites: R = 0.83, root mean square difference (RMSD) = 1.93 g C m-2 d-1) and consistency for NEE (22 sites: R = 0.56, RMSD = 1.46 g C m-2 d-1). The model simulations also tracked post-fire NEE recovery indicated from three boreal tower fire chronosequence networks but with larger model uncertainty during early succession. Annual GPP was significantly (p < 0.005) larger in warmer years than in colder years, except for Eurasian boreal forest, which showed greater drought sensitivity due to characteristic warmer, drier growing seasons relative to other areas. The NEE response to climate variability and fire was mitigated by compensating changes in GPP and respiration, though NEE carbon losses were generally observed in areas with severe drought or burning. Drought and temperature variations also had larger regional impacts on GPP and NEE than fire during the study period, though fire disturbances were heterogeneous, with larger impacts on carbon fluxes for some areas and years. These results are being used to inform development of similar operational carbon products for the NASA Soil Moisture Active Passive (SMAP) mission.

Yi, Yonghong; Kimball, John S.; Jones, Lucas A.; Reichle, Rolf H.; Nemani, Ramakrishna; Margolis, Hank A.

2013-06-01

8

The Possibilities of Communication with Extra-Terrestrial Civilizations.  

National Technical Information Service (NTIS)

CONTENTS: How many civilizations are there in the universe; Types of contacts between civilizations; Radio communication between civilizations; Radio communication between civilizations of the Earth type; Receiving information from super-civilizations. (A...

L. M. Gindilis

1966-01-01

9

Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks.  

National Technical Information Service (NTIS)

Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will in...

B. A. Kachmar G. J. Chomos J. H. Griner K. S. Martzaklis R. J. Kerczewski S. W. Mainger

2000-01-01

10

The "Ethical Paradox of Communication with Extra-Terrestrial Intelligences"  

NASA Astrophysics Data System (ADS)

Technological conditions required by the boundaries of our human intelligence to communicate with E.T. intelligence could put us within a situation in which one could abdicate a fundamental part of what it means to be human.

Lestel, D.

2010-04-01

11

Terrestrial Communications Systems in Distance Education. A Reference Booklet.  

ERIC Educational Resources Information Center

|This booklet is intended as a reference on the application of the technology of communication systems to distance education. An introductory section addresses the nature of the interaction imposed by use of various technologies. The next section overviews current telecommunications applications based on these major technologies: radio, television…

Worthington, Ross

12

Improved satellite-based emergency alerting system  

NASA Astrophysics Data System (ADS)

Rapid-onset natural hazards have claimed more than 2.8 million lives worldwide in the past 20 years. This category includes such events as earthquakes, landslides, hurricanes, tornadoes, floods, volcanic eruptions, wildfires, and tsunamis. Effective hazard mitigation is particularly difficult in such cases, since the time available to issue warnings can be very short or even nonexistent. A general approach to mitigate the effects of these disasters was demonstrated in 1988 that included preevent emergency planning, real-time hazard assessment, and rapid warning via satellite communication links. This article reports on improvements in this satellite-based emergency alerting communication system that have reduced the response time from 87 to 17 sec and expanded the broadcast coverage from 40 percent to 62 percent of the earth's surface.

Bernard, E. N.; Milburn, H. B.

1991-12-01

13

14 CFR 141.91 - Satellite bases.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Satellite bases. 141.91 Section 141.91...SCHOOLS Operating Rules § 141.91 Satellite bases. The holder of a pilot...chief instructor is designated for each satellite base, and that assistant chief...

2013-01-01

14

a Satellite-Based Radar Wind Sounder  

Microsoft Academic Search

The objective of this study is to investigate the application of Doppler radar systems for global wind measurement. A model of the satellite-based radar wind sounder (RAWS) is discussed, and many critical problems in the designing, such as the antenna scan pattern, tracking the Doppler shift caused by satellite motion, and backscattering of radar signals from different types of clouds,

Weizhuang Xin

1991-01-01

15

WNG opts for solar, satellite-based SCADA pipeline technology  

SciTech Connect

Williams Natural Gas Co., Tulsa, has installed an innovative solar-powered, satellite-based SCADA network to link 150 pipeline custody transfer sites in three states, creating a sophisticated electronic flow measurement system. Project managed by an engineering team from The Williams Companies, the new system provides the accurate, real-time flow measurement data needed to manage the company's gas pipeline network in line with the objectives of FERC Order 636. The system advances wide-area SCADA technology through the use of satellite communications systems, many of which are solar powered, to reduce costs and improve reliability of electronic flow measurement when compared to systems based on conventional leased telephone line links.

Not Available

1993-12-01

16

Brief communication "Analysis of deformations in historic urban areas using terrestrial laser scanning"  

NASA Astrophysics Data System (ADS)

The terrestrial laser scanning (TLS) technique has been used to accurately reconstruct the 3-D shape of the walls and bastions of the historic city of Mdina (Malta) and underlying terrain. By applying this technique it has also been possible to extract additional quantitative information regarding weathering and deformational processes affecting the structures. Thus, with the aim of identifying the main instability mechanisms, a detailed 3-D crack distribution map has been drawn and the main displacement vectors have been defined.

Gigli, G.; Mugnai, F.; Leoni, L.; Casagli, N.

2009-11-01

17

The Upper Valanginian (Early Cretaceous) positive carbon-isotope event recorded in terrestrial plants [rapid communication  

NASA Astrophysics Data System (ADS)

Our understanding of the ancient ocean-atmosphere system has focused on oceanic proxies. However, the study of terrestrial proxies is equally necessary to constrain our understanding of ancient climates and linkages between the terrestrial and oceanic carbon reservoirs. We have analyzed carbon-isotope ratios from fossil plant material through the Valanginian and Lower Hauterivian from a shallow-marine, ammonite-constrained succession in the Crimean Peninsula of the southern Ukraine in order to determine if the Upper Valanginian positive carbon-isotope excursion is expressed in the atmosphere. ?13C plant values fluctuate around - 23‰ to - 22‰ for the Valanginian-Hauterivian, except during the Upper Valanginian where ?13C plant values record a positive excursion to ˜- 18‰. Based upon ammonite biostratigraphy from Crimea, and in conjunction with a composite Tethyan marine ?13C carb curve, several conclusions can be drawn: (1) the ?13C plant record indicates that the atmospheric carbon reservoir was affected; (2) the defined ammonite correlations between Europe and Crimea are synchronous; and (3) a change in photosynthetic carbon-isotope fractionation, caused by a decrease in atmospheric pCO 2, occurred during the Upper Valanginian positive ?13C excursion. Our new data, combined with other paleoenvironmental and paleoclimatic information, indicate that the Upper Valanginian was a cool period (icehouse) and highlights that the Cretaceous period was interrupted by periods of cooling and was not an equable climate as previously thought.

Gröcke, Darren R.; Price, Gregory D.; Robinson, Stuart A.; Baraboshkin, Evgenij Y.; Mutterlose, Jörg; Ruffell, Alastair H.

2005-12-01

18

Design of Satellite-Based Networks for u-Health - GALENOS, DELTASS, MEDASHIP, EMISPHER  

Microsoft Academic Search

OP 2000 has implemented various satellite-based networks for telemedicine supporting the use of distributed medical intelligence. Such networks contribute to the improvement of the quality of medical care, to the cost-effective use of medical resources and to quick and reliable decisions. The high-end interactive video communication system WinVicos has been especially designed for telemedical applications like teleconsultation and second opinion

G. Graschew; T. A. Roelofs; S. Rakowsky; P. M. Schlag

2007-01-01

19

Delivery of satellite based broadband services  

NASA Astrophysics Data System (ADS)

Availability of speedy communication links to individuals and organizations is essential to keep pace with the business and social requirements of this modern age. While the PCs have been continuously growing in processing speed and memory capabilities, the availability of broadband communication links still has not been satisfactory in many parts of the world. Recognizing the need to give fillip to the growth of broadband services and improve the broadband penetration, the telecom policies of different counties have placed special emphasis on the same. While emphasis is on the use of fiber optic and copper in local loop, satellite communications systems will play an important role in quickly establishing these services in areas where fiber and other communication systems are not available and are not likely to be available for a long time to come. To make satellite communication systems attractive for the wide spread of these services in a cost effective way special emphasis has to be given on factors affecting the cost of the bandwidth and the equipment. As broadband services are bandwidth demanding, use of bandwidth efficient modulation technique and suitable system architecture are some of the important aspects that need to be examined. Further there is a need to re-look on how information services are provided keeping in view the user requirements and broadcast capability of satellite systems over wide areas. This paper addresses some of the aspects of delivering broadband services via satellite taking Indian requirement as an example.

Chandrasekhar, M. G.; Venugopal, D.

2007-06-01

20

Participant perceptions of a collaborative satellite?based mathematics course  

Microsoft Academic Search

Qualitative research methodology was used to explore the perceptions of students and classroom teachers participating in an interactive collaborative satellite?based mathematics course in twenty?one high schools. A pre? and posttest measure of college mathematics placement was used to compare students in the satellite?based course to those in a traditional precalculus course. Results showed that a collaborative satellite distance learning format

Matthew R. Larson; Roger Bruning

1996-01-01

21

An energy-efficient architecture for multi-hop communication between rovers and satellites in extra-terrestrial surfaces  

Microsoft Academic Search

Over the past three decades, several man-made vehicles have being sent into space to explore the extra-terrestrial bodies. As the search for water and other useful substances in the extra-terrestrial surfaces increases, this exploration activity is set to dramatically increase over the next decade (2020); with NASA planning to explore the surface of Mars, Moon and other planets and satellites.

Daniel Irwin; Hrishikesh Venkataraman; Gabriel-Miro Muntean

2012-01-01

22

Multi-spectral band selection for satellite-based systems  

SciTech Connect

The design of satellite based multispectral imaging systems requires the consideration of a number of tradeoffs between cost and performance. The authors have recently been involved in the design and evaluation of a satellite based multispectral sensor operating from the visible through the long wavelength IR. The criteria that led to some of the proposed designs and the modeling used to evaluate and fine tune the designs will both be discussed. These criteria emphasized the use of bands for surface temperature retrieval and the correction of atmospheric effects. The impact of cost estimate changes on the final design will also be discussed.

Clodius, W.B.; Weber, P.G.; Borel, C.C.; Smith, B.W.

1998-09-01

23

Satellite Based Synchronous Tutorials vs. Satellite Based Asynchronous Videocassettes: Factors Affecting Students' Attitudes and Choices.  

ERIC Educational Resources Information Center

The Open University of Israel (OUI) is a distance learning university. Learning is based mainly on textbooks and meetings with tutors in learning centers throughout the country. However, these meetings sometimes do not materialize. Synchronous virtual tutorials, via satellite communication from a studio at the university to classrooms throughout…

Beyth-Marom, Ruth; Saporta, Kelly

24

Simulation, modeling, and evaluation of satellite-based multicasting protocols  

Microsoft Academic Search

Satellite-based mobile multicasting is a largely unexplored and untested area of networking. This paper examines the performance associated with applying distance vector multicast routing protocol (DVMRP) and on demand multicast routing protocol (ODMRP) to a six plane, 66-satellite low Earth orbit satellite (LEOs) constellation. ODMRP provides high quality-of-service performance at the expense of bandwidth efficiency. In contrast, DVMRP is over

Ryan W. Thomas; Richard A. Raines; R. O. Baldwin; M. A. Temple

2001-01-01

25

Site-level evaluation of satellite-based global terrestrial gross ...  

Treesearch

There was strong seasonality in the MODIS GPP at all sites, and mean NPP ranged ... overestimation at the desert grassland and at the dry coniferous forest sites. ... and the climate data - revealed the causes of the over- and underestimates.

26

Satellite-based Monitoring of Environment for Human Security  

NASA Astrophysics Data System (ADS)

Global environmental change is emerging as the effect of transformation of the land, the ocean and the atmosphere driven by synergy of socio-economic and natural processes. As the progress of rapidly growing interconnectedness in the world, we have begun to induce the planetary scale change in our own life support system. Especially African environment is vulnerable to climate change and affecting human security in a broad sense. This paper describes needs for geoinformation and corresponding JAXA's satellite-based monitoring of environment.

Igarashi, Tamotsu

27

Communication.  

ERIC Educational Resources Information Center

|The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of…

Strauss, Andre

28

Global Terrestrial Observing System  

NSDL National Science Digital Library

The Global Terrestrial Observing System (GTOS) is used to facilitate communication regarding world ecological research networks. There are also tools on this website to describe the three regional observation programs in Southern Africa and Central and Eastern Europe. The shared information includes data on Net Primary Production (NPP), Terrestrial Carbon Observation (TCO), Terrestrial Panel on Climate (TOPC), and Global Observation of Landcover Dynamics. Users can also access Terrestrial Ecosystem Monitoring Sites (TEMS), which concentrate on remote sensing data collection from over 500 individual sites located in primarily mountain or coastal regions. The TEMS program began in the early 1990's and is the international equivalent of Long Term Ecological Research sites found primarily in North America. TEMS are used to link ground and remotely sensed observations as well as to provide temporal assessment of ecological conditions. Other general data collected includes land quality, water resources, climate change, biodiversity, pollution and toxicity, global/ regional/ national environments, and international conventions.

2002-01-17

29

[Surveying a zoological facility through satellite-based geodesy].  

PubMed

In the course of a thesis submitted for a diploma degree within the Fachhochschule Oldenburg the Serengeti Safaripark was surveyed in autumn and winter 1996/97 laying in the planning foundations for the application for licences from the controlling authorities. Taking into consideration the special way of keeping animals in the Serengeti Safaripark (game ranching, spacious walk-through-facilities) the intention was to employ the outstanding satellite based geodesy. This technology relies on special aerials receiving signals from 24 satellites which circle around the globe. These data are being gathered and examined. This examination produces the exact position of this aerial in a system of coordinates which allows depicting this point on a map. This procedure was used stationary (from a strictly defined point) as well as in the movement (in a moving car). Additionally conventional procedures were used when the satellite based geodesy came to its limits. Finally a detailed map of the Serengeti Safaripark was created which shows the position and size of stables and enclosures as well as wood and water areas and the sectors of the leisure park. Furthermore the established areas of the enclosures together with an already existing animal databank have flown into an information system with the help of which the stock of animals can be managed enclosure-orientated. PMID:10916935

Böer, M; Thien, W; Tölke, D

2000-06-01

30

Satellite-based studies on large-scale vegetation changes in China.  

PubMed

Remotely-sensed vegetation indices, which indicate the density and photosynthetic capacity of vegetation, have been widely used to monitor vegetation dynamics over broad areas. In this paper, we reviewed satellite-based studies on vegetation cover changes, biomass and productivity variations, phenological dynamics, desertification, and grassland degradation in China that occurred over the past 2-3 decades. Our review shows that the satellite-derived index (Normalized Difference Vegetation Index, NDVI) during growing season and the vegetation net primary productivity in major terrestrial ecosystems (for example forests, grasslands, shrubs, and croplands) have significantly increased, while the number of fresh lakes and vegetation coverage in urban regions have experienced a substantial decline. The start of the growing season continually advanced in China's temperate regions until the 1990s, with a large spatial heterogeneity. We also found that the coverage of sparsely-vegetated areas declined, and the NDVI per unit in vegetated areas increased in arid and semi-arid regions because of increased vegetation activity in grassland and oasis areas. However, these results depend strongly not only on the periods chosen for investigation, but also on factors such as data sources, changes in detection methods, and geospatial heterogeneity. Therefore, we should be cautious when applying remote sensing techniques to monitor vegetation structures, functions, and changes. PMID:22974506

Zhao, Xia; Zhou, Daojing; Fang, Jingyun

2012-10-01

31

Validation of the Global NASA Satellite-based Flood Detection System in Bangladesh  

NASA Astrophysics Data System (ADS)

Floods are one of the most destructive natural forces on earth, affecting millions of people annually. Nations lying in the downstream end of an international river basin often suffer the most damage during flooding and could benefit from the real-time communication of rainfall and stream flow data from countries upstream. This is less likely to happen among developing nations due to a lack of freshwater treaties (Balthrop and Hossain, Water Policy, 2009). A more viable option is for flood-prone developing nations to utilize the global satellite rainfall and modeled runoff data that is independently and freely available from the NASA Satellite-based Global Flood Detection System. Although the NASA Global Flood Detection System has been in operation in real-time since 2006, the ‘detection’ capability of flooding has only been validated against qualitative reports in news papers and other types of media. In this study, a more quantitative validation against in-situ measurements of the flood detection system over Bangladesh is presented. Using ground-measured stream flow data as well as satellite-based flood potential and rainfall data, the study looks into the relationship between rainfall and flood potential, rainfall and stream flow, and stream flow and flood potential for three very distinct river systems in Bangladesh - 1) Ganges- a snow-fed river regulated by upstream India 2) Brahmaputra - a snow-fed river that is also braided 3) Meghna - a rain-fed river. The quantitative assessment will show the effectiveness of the NASA Global Flood Detection System for a very humid and flood prone region like Bangladesh that is also faced with tremendous transboundary hurdles that can only be resolved from the vantage of space.

Moffitt, C. B.

2009-12-01

32

Interoperability of satellite-based augmentation systems for aircraft navigation  

NASA Astrophysics Data System (ADS)

The Federal Aviation Administration (FAA) is pioneering a transformation of the national airspace system from its present ground based navigation and landing systems to a satellite based system using the Global Positioning System (GPS). To meet the critical safety-of-life aviation positioning requirements, a Satellite-Based Augmentation System (SBAS), the Wide Area Augmentation System (WAAS), is being implemented to support navigation for all phases of flight, including Category I precision approach. The system is designed to be used as a primary means of navigation, capable of meeting the Required Navigation Performance (RNP), and therefore must satisfy the accuracy, integrity, continuity and availability requirements. In recent years there has been international acceptance of Global Navigation Satellite Systems (GNSS), spurring widespread growth in the independent development of SBASs. Besides the FAA's WAAS, the European Geostationary Navigation Overlay Service System (EGNOS) and the Japan Civil Aviation Bureau's MTSAT-Satellite Augmentation System (MSAS) are also being actively developed. Although all of these SBASs can operate as stand-alone, regional systems, there is increasing interest in linking these SBASs together to reduce costs while improving service coverage. This research investigated the coverage and availability improvements due to cooperative efforts among regional SBAS networks. The primary goal was to identify the optimal interoperation strategies in terms of performance, complexity and practicality. The core algorithms associated with the most promising concepts were developed and demonstrated. Experimental verification of the most promising concepts was conducted using data collected from a joint international test between the National Satellite Test Bed (NSTB) and the EGNOS System Test Bed (ESTB). This research clearly shows that a simple switch between SBASs made by the airborne equipment is the most effective choice for achieving the desired interoperability. It yields at least 95% of the availability benefit achievable with a much more expensive optimal solution. Other more complex scenarios generally do not provide greater benefit, and create greater algorithm complexity and typically have significant infrastructure cost increases. Therefore, the airborne switching approach is highly recommended and should be adopted as the interoperability standard.

Dai, Donghai

33

Satellite -Based Networks for U-Health & U-Learning  

NASA Astrophysics Data System (ADS)

The use of modern Information and Communication Technologies (ICT) as enabling tools for healthcare services (eHealth) introduces new ways of creating ubiquitous access to high-level medical care for all, anytime and anywhere (uHealth). Satellite communication constitutes one of the most flexible methods of broadband communication offering high reliability and cost-effectiveness of connections meeting telemedicine communication requirements. Global networks and the use of computers for educational purposes stimulate and support the development of virtual universities for e-learning. Especially real-time interactive applications can play an important role in tailored and personalised services.

Graschew, G.; Roelofs, T. A.; Rakowsky, S.; Schlag, P. M.

2008-08-01

34

Satellite-based monitoring of air quality within QUITSAT project  

NASA Astrophysics Data System (ADS)

Satellite remote sensing of both trace gas constituents and Particulate Matter (PM) can be profitably exploited in Air Quality (AQ) assessment. The actual potential role of satellite observations is here highlighted combined with regional meteorological and Chemical Transport Models (CTM) in the context of air quality monitoring as experienced in QUITSAT Project over Northern Italy (from 43:09 to 46:39 N, from 6:19 to 14:23 E). QUITSAT (2006-2009) is a pilot project funded by the Italian Space Agency (ASI) in the framework of its institutional priorities for the Natural and Technological disaster management programme. AQ monitoring is in general based on local ground measurements. In recent years, this issue has been inserted in a more extended frame, in which CTM have joined ground-based data and satellite observations to provide a better characterization of AQ monitoring, forecasting and planning on a regional scale. In particular, two satellite-based products arisen from analysis methodologies developed in QUITSAT and relative to significant pollutants as PM2.5 and NO2 are presented within this work. The MODIS sensors capability (Terra and Aqua/NASA platforms) to retrieve Aerosol Optical Properties (AOP) has been used in a semi-empirical approach to estimate PM2.5 content at the ground. At first, PM2.5 concentration sampled in several sites over Northern Italy are employed in order to infer AOP to PM conversion parameters. A spatial-temporal coincidence procedure has been performed amongst EO and non-EO data. To take into account the aerosol columnar dispersion and the AOP dependence on the relative humidity (RH) meteorological fields (Planetary Boundary Layer and RH) simulated by MM5 are considered. MODIS aerosol level 2 products (MOD04 and MYD04 collection 5, 10x10 km2 spatial resolution) and PM2.5 samplings performed by Regional Environmental Agencies (ARPA Emilia Romagna and ARPA Lombardia) and carried out over further 6 measurements sites (located in Milano, Bologna, S. Pietro Capofiume, Oasi Bine, Monte Cimone e Bormio) relative to 2004, summer 2007 and winter 2008, are employed to derive the best regression parameters for AOD to PM2.5 conversion relationship. The conversion parameters have been grouped on a monthly basis and spatially interpolated over the whole domain. Thus, daily maps of satellite-based PM2.5 concentrations over Northern Italy are derived. Monthly averaged values have been compared to in-situ PM2.5 sampling providing a good agreement. OMI (Aura/NASA platform) NO2 tropospheric column (spatial resolution 13x24 km2) are merged with the simulations of the Transport Chemical Aerosol Model (TCAM) performed at resolution of 5x5 km2. The method used is a weighted rescaling of the model column in the troposphere according to the OMI observations, where the weights are the measurement errors and the model column variances within the satellite ground-pixel, respectively. Nitrogen dioxide above the TCAM maximum modelled altitude (that is about 4 km) are considered as negligible in our approach. Actually this is a good approximation when medium and high polluted regions are observed (as Northern Italy) while further analysis could be required over low polluted regions to exclude any significant NO2 amount in the middle and upper troposphere. The obtained ground concentrations of NO2 have been compared with in-situ observations performed by the Regional Environmental Agencies (ARPA Emilia Romagna and ARPA Lombardia) showing good agreement either over rural area or over urban region where horizontal gradient in NO2 concentration could be relevant. The work is part of the pilot project QUITSAT, funded by the Italian Space Agency (ASI), contract I/035/06/0, http://www.quitsat.it.

di Nicolantonio, W.

2009-04-01

35

Communications.  

National Technical Information Service (NTIS)

Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effect...

D. D. Stouffer

1990-01-01

36

Operational Satellite-based Surface Oil Analyses (Invited)  

NASA Astrophysics Data System (ADS)

During the Deepwater Horizon spill, NOAA imagery analysts in the Satellite Analysis Branch (SAB) issued more than 300 near-real-time satellite-based oil spill analyses. These analyses were used by the oil spill response community for planning, issuing surface oil trajectories and tasking assets (e.g., oil containment booms, skimmers, overflights). SAB analysts used both Synthetic Aperture Radar (SAR) and high resolution visible/near IR multispectral satellite imagery as well as a variety of ancillary datasets. Satellite imagery used included ENVISAT ASAR (ESA), TerraSAR-X (DLR), Cosmo-Skymed (ASI), ALOS (JAXA), Radarsat (MDA), ENVISAT MERIS (ESA), SPOT (SPOT Image Corp.), Aster (NASA), MODIS (NASA), and AVHRR (NOAA). Ancillary datasets included ocean current information, wind information, location of natural oil seeps and a variety of in situ oil observations. The analyses were available as jpegs, pdfs, shapefiles and through Google, KML files and also available on a variety of websites including Geoplatform and ERMA. From the very first analysis issued just 5 hours after the rig sank through the final analysis issued in August, the complete archive is still publicly available on the NOAA/NESDIS website http://www.ssd.noaa.gov/PS/MPS/deepwater.html SAB personnel also served as the Deepwater Horizon International Disaster Charter Project Manager (at the official request of the USGS). The Project Manager’s primary responsibility was to acquire and oversee the processing and dissemination of satellite data generously donated by numerous private companies and nations in support of the oil spill response including some of the imagery described above. SAB has begun to address a number of goals that will improve our routine oil spill response as well as help assure that we are ready for the next spill of national significance. We hope to (1) secure a steady, abundant and timely stream of suitable satellite imagery even in the absence of large-scale emergencies such as Deepwater Horizon, (2) acquire a 24 x 7 oil spill response capability at least on a pre-operational basis, (3) acquire improved and expanded ancillary datasets, (4) reduce the number of false positives (analyzed oil that is not actually oil), (5) acquire the ability to reliably differentiate, at least in general qualitative terms, thick oil (“recoverable oil”) from oil sheens, and (6) join our Canadian counterparts (the Integrated Satellite Tracking of Pollution group in Environment Canada) to create a joint North American center for oil spill response.

Streett, D.; Warren, C.

2010-12-01

37

Satellite-based Wetland Mapping in High Latitudes  

NASA Astrophysics Data System (ADS)

The flat terrain with poor drainage in high-latitude regions yields excessive wetlands characterized by saturated soil and riparian vegetation. These wetlands have long been recognized for their importance in the global carbon and hydrological cycles and continue to receive substantial attention. As a part of our NASA THP (Terrestrial Hydrology Program) project to assess recent terrestrial water storage change in Arctic lakes and wetlands, this paper addresses wetland mapping using remote sensing. Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) have been widely used in wetland mapping to quantify vegetation and underlying surface water. However, the performance of such indices is limited by the "mixed pixel" effect due to the fact that a wetland pixel comprises of mixed spectral responses of water and vegetation. Hence, we propose to estimate the abundance of each of these surface materials within a pixel through a spectral unmixing approach. The general assumption in spectral unmixing is that the observed pixel spectrum is a linear combination of several endmembers denoting pure material spectra available in existing spectral libraries. The limited and poor availability of ground truth in regional-scale research however prohibits the use of library spectra, necessitating the use of unsupervised spectral unmixing techniques. The proposed research applies independent component analysis (ICA) to perform a non-orthogonal linear transformation of the multi-spectral Landsat images for an unsupervised spectral unmixing to obtain water and vegetation abundances, which are crucial to wetland mapping. The method is highly efficient with a high-level of replicability and automation. Performance of the proposed approach is evaluated quantitatively, and a high accuracy is achieved in high-latitude wetland mapping.

Shah, C. A.; Sheng, Y.; Smith, L. C.; Li, J.; Lyons, E.; Hinkel, K. M.; Winston, B.

2008-12-01

38

Analysis of laser jamming to satellite-based detector  

Microsoft Academic Search

The reconnaissance satellite, communication satellite and navigation satellite used in the military applications have played more and more important role in the advanced technique wars and already become the significant support and aid system for military actions. With the development of all kinds of satellites, anti-satellite laser weapons emerge as the times require. The experiments and analyses of laser disturbing

Si-Wen Wang; Li-Hong Guo; Ru-Hai Guo

2009-01-01

39

GIO-EMS and International Collaboration in Satellite based Emergency Mapping  

NASA Astrophysics Data System (ADS)

During the last decade, satellite based emergency mapping has developed into a mature operational stage. The European Union's GMES Initial Operations - Emergency Management Service (GIO-EMS), is operational since April 2012. It's set up differs from other mechanisms (for example from the International Charter "Space and Major Disasters"), as it extends fast satellite tasking and delivery with the value adding map production as a single service, which is available, free of charge, to the authorized users of the service. Maps and vector datasets with standard characteristics and formats ranging from post-disaster damage assessment to recovery and disaster prevention are covered by this initiative. Main users of the service are European civil protection authorities and international organizations active in humanitarian aid. All non-sensitive outputs of the service are accessible to the public. The European Commission's in-house science service Joint Research Centre (JRC) is the technical and administrative supervisor of the GIO-EMS. The EC's DG ECHO Monitoring and Information Centre acts as the service's focal point and DG ENTR is responsible for overall service governance. GIO-EMS also aims to contribute to the synergy with similar existing mechanisms at national and international level. The usage of satellite data for emergency mapping has increased during the last years and this trend is expected to continue because of easier accessibility to suitable satellite and other relevant data in the near future. Furthermore, the data and analyses coming from volunteer emergency mapping communities are expected to further enrich the content of such cartographic products. In the case of major disasters the parallel activity of more providers is likely to generate non-optimal use of resources, e.g. unnecessary duplication; whereas coordination may lead to reduced time needed to cover the disaster area. Furthermore the abundant number of geospatial products of different characteristics and quality can become confusing for users. The urgent need for a better coordination has led to establishment of the International Working Group on Satellite Based Emergency Mapping (IWG-SEM). Members of the IWG-SEM, which include JRC, USGS, DLR-ZKI, SERVIR, Sentinel Asia, UNOSAT, UN-SPIDER, GEO, ITHACA and SERTIT have recognized the need to establish the best practice between operational satellite-based emergency mapping programs. The group intends to: • work with the appropriate organizations on definition of professional standards for emergency mapping, guidelines for product generation and reviewing relevant technical standards and protocols • facilitate communication and collaboration during the major emergencies • stimulate coordination of expertise and capacities. The existence of the group and the cooperation among members already brought benefits during recent disasters in Africa and Europe in 2012 in terms of faster and effective satellite data provision and better product generation.

Kucera, Jan; Lemoine, Guido; Broglia, Marco

2013-04-01

40

TERRESTRIAL ECOTOXICOLOGY  

EPA Science Inventory

Terrestrial ecotoxicology is the study of how environmental pollutants affect land-dependent organisms and their environment. It requires three elements: (1) a source, (2) a receptor, and (3) an exposure pathway. This article reviews the basic principles of each of each element...

41

The planned satellite-based maritime distress call system  

NASA Astrophysics Data System (ADS)

A terrestrial system designed for use in the testing of transmission options for a maritime distress call system based on satellite emergency position-indicating radio beacons is presented. The components described, consisting of three sea-rescue buoys and the related receiving and evaluation installation, form part of a system in which the buoy transmits the last known position of a ship in distress via an INMARSAT geostationary satellite. The buoys contain an L-band synthesizer, 10-W power amplifier, encoder with interface to the shipboard navigation system, and antenna. The reception and evaluation installation functions to improve the signal-to-noise ratio in order to allow detection of the distress call based on a computer-assisted multichannel receiver with integrated error correction capability, which is capable of evaluating simultaneously three channels out of the 240 in its 3600 Hz bandwidth. By the use of such a system, the position of a ship in distress may be learned within 8 minutes for transmission outputs of 2.5 W or less.

Kesenheimer, H.

42

Communicate!  

ERIC Educational Resources Information Center

|This ten chapter book is designed to provide high school students with an understanding of basic communication processes. The first five chapters include discussions of language development, function, and acquisition in relation to both human and non-human communication. The sixth chapter contains specimen linguistic analyses of speech and…

Chase, Stuart

43

Comparative Evaluation of NEXRAD and TRMM Satellite based Precipitation Estimates and Rain Gage Measurements  

NASA Astrophysics Data System (ADS)

The availability of accurate precipitation data is essential for hydrologic modeling and water resources management. Recent advances NEXRAD and satellite based measurements have provided alternative methods for precipitation estimation. The current study focuses on comparative evaluation and assessment of TRMM (Tropical Rainfall Measuring Mission) satellite based precipitation estimates. Multi-sensor estimate based precipitation data available in the form of 4km x 4 km HRAP (hydrologic rainfall analysis project) and 2 km x 2 km NEXRAD grid based precipitation estimates, and rain gage measurements available in a specific region of South Florida region were used for comparison with the TRMM based precipitation measurements. The utility of satellite-based precipitation data is also evaluated for infilling missing precipitation data at rain gages. A total of 58 rain gages in this region were used as ground truth to assess the quality of precipitation estimates. Preliminary results suggest that TRMM satellite based precipitation estimates compare well with NEXRAD and rain gage measurements.

Meskele, T.; Teegavarapu, R. S.; Pathak, C.

2008-12-01

44

Impact of atmospheric variability on validation of satellite-based temperature measurements  

NASA Astrophysics Data System (ADS)

Satellite validation is often based on straight forward comparison of satellite-based data with non-satellite based measurements. For functional reasons satellite and reference measurements do usually not correspond exactly in time and space. Dynamical effects in the atmosphere lead to temporal and spatial variability of atmospheric parameters (e.g. temperature). This causes considerable differences that do not necessarily hint to an incorrect satellite measurement, so called mistime and misdistance errors.

Wendt, Verena; Wüst, Sabine; Mlynczak, Martin G.; Russell, James M.; Yee, Jeng-Hwa; Bittner, Michael

2013-09-01

45

Communication  

Microsoft Academic Search

\\u000a Communication impairment is a core deficit associated with autism spectrum disorder (ASD). Therefore, it should not be surprising\\u000a that this topic has become a major thrust of assessment and treatment in applied behavior analysis (ABA). The types of communication\\u000a skills to target for intervention and the behavioral assessment methods that can be used to identify these target behaviors\\u000a are reviewed

Jeff Sigafoos; Mark F. O’Reilly; Giulio E. Lancioni

46

Short communication Detection of Deformed wing virus, a honey bee viral pathogen, in bumble bees (Bombus terrestris and Bombus pascuorum) with wing deformities  

Microsoft Academic Search

Honey bees (Apis mellifera) productively infected with Deformed wing virus (DWV) through Varroa destructor (V. destructor) during pupal stages develop into adults showing wing and other morphological deformities. Here, we report for the Wrst time the occurrence of bumble bees (Bombus terrestris, Bombus pascuorum) exhibiting wing deformities resembling those seen in clinically DWV-infected honey bees. Using speciWc RT-PCR protocols for

Elke Genersch; Constanze Yue; Ingemar Fries; Joachim R. de Miranda

2006-01-01

47

Validation of PV performance models using satellite-based irradiance measurements : a case study.  

SciTech Connect

Photovoltaic (PV) system performance models are relied upon to provide accurate predictions of energy production for proposed and existing PV systems under a wide variety of environmental conditions. Ground based meteorological measurements are only available from a relatively small number of locations. In contrast, satellite-based radiation and weather data (e.g., SUNY database) are becoming increasingly available for most locations in North America, Europe, and Asia on a 10 x 10 km grid or better. This paper presents a study of how PV performance model results are affected when satellite-based weather data is used in place of ground-based measurements.

Stein, Joshua S.; Parkins, Andrew (Clean Power Research); Perez, Richard (University at Albany)

2010-05-01

48

Comparison of two satellite-based rainfall algorithms using pacific atoll raingage data  

Microsoft Academic Search

Rainfall estimates for two simple satellite-based rainfall algorithms are verified over the tropical Pacific using a new method that incorporates sparsely distributed raingages. The resulting linear regression relationship between monthly areal rainfall and the highly reflective cloud index agrees with earlier results. However, the GOES precipitation index (GPI), which was calibrated using radar rainfall data obtained from the eastern tropical

Mark L. Morrissey; J. Scott Greene

1993-01-01

49

Using generalized linear models to enhance satellite-based land cover change detection  

Microsoft Academic Search

A popular satellite based land cover change detection technique is used to compare the spectral information for each pixel, from two images acquired at different dates. For each pixel, if there is a big enough difference between the reflectance values from the two images, the area represented by that pixel is considered to have changed. The change detection methods are

Jeffrey Thomas Morisette

1997-01-01

50

Multi Attribute Based Algorithm for Reliable Satellite-Based Sensor Networks  

Microsoft Academic Search

Modern environmental monitoring systems are based on satellite-based sensor networks (SSN) where earth stations (Sinks) gather information from sensors and use the satellite channel to send it to remote sites. For the sake of efficiency of a whole monitoring system, the SSN has to be managed by following two main aims: to guarantee the reliability, in particular in case of

Igor Bisio; Mario Marchese; Giancarlo Portomauro

2007-01-01

51

Tropospheric Delay Correction of GNSS Signals for Satellite-Based Augmentation System  

Microsoft Academic Search

A strategy to realize the tropospheric delay correction in satellite based augmentation systems is presented. The tropospheric delay is one of the major error sources of the GNSS signals. It is attempted to generate the correction information from the numerical weather prediction data to realize the tropospheric delay correction in real-time for mobile positioning. To introduce the correction information into

Noboru Takeichi; Takeyasu Sakai; Sounosuke Fukushima; Ken Ito

2007-01-01

52

GLOBAL MOBILE SATELLITE COMMUNICATIONS: A REVIEW OF THREE CONTENDERS  

Microsoft Academic Search

The era of satellite-based mobile communications systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept mobile satellite communications (MSC) systems from appealing to the wider market of personal mobile communications.

Gary M. Comparetto

1994-01-01

53

Satellite-Based Energy Balance for Mapping Evapotranspiration with Internalized Calibration (METRIC)—Model  

Microsoft Academic Search

Mapping evapotranspiration at high resolution with internalized calibration METRIC is a satellite-based image-processing model for calculating evapotranspiration ET as a residual of the surface energy balance. METRIC uses as its foundation the pioneering SEBAL energy balance process developed in The Netherlands by Bastiaanssen, where the near-surface temperature gradients are an indexed function of radiometric surface temperature, thereby eliminating the need

Richard G. Allen; Masahiro Tasumi; Ricardo Trezza

2007-01-01

54

Satellite communications for aeronautical and navigation service  

NASA Astrophysics Data System (ADS)

This paper describes the satellite-based systems to be used by the civil aviation community to meet the future communications, navigation and surveillance requirements for air traffic management over oceans and remote land areas, as well as for other aeronautical mobile communications purposes.

Smith, Richard

55

Spatio-temporal validation of satellite-based rainfall estimates in the Philippines  

NASA Astrophysics Data System (ADS)

Satellite-based rainfall is an alternative source of information especially for developing countries such as the Philippines where there are many areas that do not have ground observation stations. To maximize the use and potential of the derived precipitation products, it is important to validate these with observation datasets. In this study, two satellite-based rainfall products, CMORPH and TRMM, are compared with observation from eight ground stations in the Philippines and the gridded rainfall dataset, APHRODITE, for 2003 to 2005. Results show that TRMM data give slightly better estimates than CMORPH but both, in general, do not correlate well with observations for all stations. Rainfall during the months of August to December are estimated better by both satellite-based data sets. TRMM and CMORPH also appear to capture well extreme precipitation in the range of 50-200 mm/day. TRMM data, in particular, is able to illustrate the areas consistently affected by frequent occurrences of high rainfall amounts. Spatial correlations show that TRMM and CMORPH perform better in the northeast regions of the Philippines but fail to estimate rainfall in the southern areas. The results indicate that the performance of satellite-derived rainfall products can be dependent on geographical location and the amount of rainfall that is estimated.

Jamandre, C. A.; Narisma, G. T.

2013-03-01

56

Experiences from near-real-time satellite-based volcano monitoring in Central America: case studies at Fuego, Guatemala  

Microsoft Academic Search

Over the past decade, remote sensing has been used increasingly in the study of active volcanoes and their associated hazards. Ground?based remote sensing techniques, such as those aimed at the analysis of volcanic gases or fumarole temperatures, are now part of routine monitoring operations with additional satellite?based remote sensing methods. It is likely that the use of satellite?based systems will

P. W. Webley; M. J. Wooster; W. Strauch; J. A. Saballos; K. Dill; P. Stephenson; J. Stephenson; R. Escobar Wolf; O. Matias

2008-01-01

57

Coordinated ground-based and geosynchronous satellite-based measurements of auroral pulsations  

SciTech Connect

We describe a technique that uses a ground-based all-sky video camera and geosynchronous satellite-based plasma and energetic particle detectors to study ionosphere-magnetosphere coupling as it relates to the aurora. The video camera system was deployed in Eagle, Alaska for a seven month period at the foot of the magnetic field line that threads geosynchronous satellite 1989-046. Since 1989-046 corotates with the earth, its footprint remains nearly fixed in the vicinity of Eagle, allowing for routine continuous monitoring of an auroral field line at its intersections with the ground and with geosynchronous orbit. As an example of the utility of this technique, we present coordinated ground-based and satellite based observations during periods of auroral pulsations and compare this data to the predictions of both the relaxation oscillator theory and flow cyclotron maser theory for the generation of pulsating aurorae. The observed plasma and energetic particle characteristics at geosynchronous orbit during pulsating aurorae displays are found to be in agreement with the predictions of both theories lending further support that a cyclotron resonance mechanism is responsible for auroral pulsations.

Suszcynsky, David M.; Borovsky, Joseph E.; Thomsen, Michelle F.; McComas, David J.; Belian, Richard D.

1996-09-01

58

Assimilating satellite-based snow depth and snow cover products for improving snow predictions in Alaska  

NASA Astrophysics Data System (ADS)

Several satellite-based snow products are assimilated, both separately and jointly, into the Noah land surface model for improving snow prediction in Alaska. These include the standard and interpreted versions of snow cover fraction (SCF) data from the Moderate-Resolution Imaging Spectroradiometer (MODIS) and the snow depth (SD) estimates from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). The satellite-based SD estimates are adjusted against in situ observations via statistical interpolation to reduce the potentially large biases, prior to being assimilated using an ensemble Kalman filter. A customized, rule-based direct insertion approach is developed to assimilate the two SCF datasets. Our results indicate that considerable overall improvement on snow prediction can be achieved via assimilating the bias-adjusted satellite SD estimates; however, the improvement does not always translate into improvements in streamflow prediction. Assimilating the standard MODIS SCF is found to have little impact on snow and streamflow predictions, while assimilating the interpreted SCF estimates, which have reduced cloud coverage and improved snow mapping accuracy, has resulted in the most consistent improvements on snow and streamflow predictions across the study domain.

Liu, Yuqiong; Peters-Lidard, Christa D.; Kumar, Sujay; Foster, James L.; Shaw, Michael; Tian, Yudong; Fall, Gregory M.

2013-04-01

59

Tropospheric Delay Correction of GNSS Signals for Satellite-Based Augmentation System  

NASA Astrophysics Data System (ADS)

A strategy to realize the tropospheric delay correction in satellite based augmentation systems is presented. The tropospheric delay is one of the major error sources of the GNSS signals. It is attempted to generate the correction information from the numerical weather prediction data to realize the tropospheric delay correction in real-time for mobile positioning. To introduce the correction information into the satellite based augmentation system, the amount of the correction data must be minimized without degrading the correction accuracy. In this paper, through several statistical evaluations using the long-term observation data, the appropriate contents and the data amount of the correction message are investigated. It is shown that the correction message should consist of the information of the tropospheric zenith delay and its average gradient in height. The amount of the correction data is also successfully minimized, and users in the region of Japan can receive the sufficient correction information by receiving only 3 messages. The results of the analyses clearly show the feasibility of the presented strategy.

Takeichi, Noboru; Sakai, Takeyasu; Fukushima, Sounosuke; Ito, Ken

60

A near real-time satellite-based global drought climate data record  

NASA Astrophysics Data System (ADS)

Reliable drought monitoring requires long-term and continuous precipitation data. High resolution satellite measurements provide valuable precipitation information on a quasi-global scale. However, their short lengths of records limit their applications in drought monitoring. In addition to this limitation, long-term low resolution satellite-based gauge-adjusted data sets such as the Global Precipitation Climatology Project (GPCP) one are not available in near real-time form for timely drought monitoring. This study bridges the gap between low resolution long-term satellite gauge-adjusted data and the emerging high resolution satellite precipitation data sets to create a long-term climate data record of droughts. To accomplish this, a Bayesian correction algorithm is used to combine GPCP data with real-time satellite precipitation data sets for drought monitoring and analysis. The results showed that the combined data sets after the Bayesian correction were a significant improvement compared to the uncorrected data. Furthermore, several recent major droughts such as the 2011 Texas, 2010 Amazon and 2010 Horn of Africa droughts were detected in the combined real-time and long-term satellite observations. This highlights the potential application of satellite precipitation data for regional to global drought monitoring. The final product is a real-time data-driven satellite-based standardized precipitation index that can be used for drought monitoring especially over remote and/or ungauged regions.

AghaKouchak, Amir; Nakhjiri, Navid

2012-12-01

61

Towards a more objective evaluation of modelled land-carbon trends using atmospheric CO2 and satellite-based vegetation activity observations  

NASA Astrophysics Data System (ADS)

Terrestrial ecosystem models used for Earth system modelling show a significant divergence in future patterns of ecosystem processes, in particular the net land-atmosphere carbon exchanges, despite a seemingly common behaviour for the contemporary period. An in-depth evaluation of these models is hence of high importance to better understand the reasons for this disagreement. Here, we develop an extension for existing benchmarking systems by making use of the complementary information contained in the observational records of atmospheric CO2 and remotely sensed vegetation activity to provide a novel set of diagnostics of ecosystem responses to climate variability in the last 30 yr at different temporal and spatial scales. The selection of observational characteristics (traits) specifically considers the robustness of information given that the uncertainty of both data and evaluation methodology is largely unknown or difficult to quantify. Based on these considerations, we introduce a baseline benchmark - a minimum test that any model has to pass - to provide a more objective, quantitative evaluation framework. The benchmarking strategy can be used for any land surface model, either driven by observed meteorology or coupled to a climate model. We apply this framework to evaluate the offline version of the MPI Earth System Model's land surface scheme JSBACH. We demonstrate that the complementary use of atmospheric CO2 and satellite-based vegetation activity data allows pinpointing of specific model deficiencies that would not be possible by the sole use of atmospheric CO2 observations.

Dalmonech, D.; Zaehle, S.

2013-06-01

62

Satellite-based snow identification and its impact on monitoring photovoltaic systems  

SciTech Connect

Earth observation allows the separation of snow cover and cloudiness using multispectral measurements. Several satellite-based snow monitoring services are available, ranging from regional to world-wide scales. Using these data enables photovoltaic (PV) plant management to differentiate between failures due to snow coverage on a PV system and other error sources. Additionally, yield estimates for solar siting are improved. This paper presents a validation study from January to April 2006 comparing satellite-based datasets with ground measurements from German and Swiss meteorological stations. A false alarm rate, an error due to irradiance underestimation, the availability of daily data, and the classification accuracy are introduced as quality metrics. Compared to Switzerland, generally a higher accuracy is found in all datasets for Southern Germany. The most significant difference among the datasets is found in the error pattern shifting from too much snow (which results in an error due to underestimation of irradiance) to too little snow detection, causing a false alarm in PV monitoring. Overall, the data records of the Land Surface Analysis Satellite Application Facility (LSA SAF), the German Aerospace Center (DLR) and the Interactive Multisensor Snow and Ice Mapping System (IMS) are found to be most suitable for solar energy purposes. The IMS dataset has a low false alarm rate (4%) and a good data availability (100%) making it a good choice for power plant monitoring, but the error due to underestimation relevant in site auditing is large with 59%. If a cumulative snow cover algorithm is applied to achieve information every day as needed both for power plant monitoring and site auditing, both the DLR and the LSA SAF datasets are comparable with classification accuracies of 70%, false alarm rates of 37% and 34%, respectively, and errors due to irradiance underestimation in 26% and 27% of all coincidences. (author)

Wirth, Georg; Zehner, Mike; Becker, Gerd [University of Applied Sciences - Munich, Department of Electrical Engineering, Solar Technology Laboratory, Lothstrasse. 64, 80323 Munich (Germany); Schroedter-Homscheidt, Marion [German Aerospace Center (DLR), German Remote Sensing Data Center (DFD), Oberpfaffenhofen, P.O. Box 1116, 82234 Wessling (Germany)

2010-02-15

63

Current trends in satellite based emergency mapping - the need for harmonisation  

NASA Astrophysics Data System (ADS)

During the past years, the availability and use of satellite image data to support disaster management and humanitarian relief organisations has largely increased. The automation and data processing techniques are greatly improving as well as the capacity in accessing and processing satellite imagery in getting better globally. More and more global activities via the internet and through global organisations like the United Nations or the International Charter Space and Major Disaster engage in the topic, while at the same time, more and more national or local centres engage rapid mapping operations and activities. In order to make even more effective use of this very positive increase of capacity, for the sake of operational provision of analysis results, for fast validation of satellite derived damage assessments, for better cooperation in the joint inter agency generation of rapid mapping products and for general scientific use, rapid mapping results in general need to be better harmonized, if not even standardized. In this presentation, experiences from various years of rapid mapping gained by the DLR Center for satellite based Crisis Information (ZKI) within the context of the national activities, the International Charter Space and Major Disasters, GMES/Copernicus etc. are reported. Furthermore, an overview on how automation, quality assurance and optimization can be achieved through standard operation procedures within a rapid mapping workflow is given. Building on this long term rapid mapping experience, and building on the DLR initiative to set in pace an "International Working Group on Satellite Based Emergency Mapping" current trends in rapid mapping are discussed and thoughts on how the sharing of rapid mapping information can be optimized by harmonizing analysis results and data structures are presented. Such an harmonization of analysis procedures, nomenclatures and representations of data as well as meta data are the basis to better cooperate within the global rapid mapping community throughout local/national, regional/supranational and global scales

Voigt, Stefan

2013-04-01

64

Desert Storm communications  

Microsoft Academic Search

An overview of the communication network that supported Operation Desert Storm is presented. The system, which maintained a 98% availability rate, supported 700000 telephone calls and 152000 messages per day. More than 30000 radio frequencies were managed to provide necessary connectivity and to ensure minimum interference. The roles of communications satellites, switched networks and terrestrial systems, and packet-switched networks and

J. S. Toma

1992-01-01

65

Information and communication technology in disease surveillance, India: a case study.  

PubMed

India has made appreciable progress and continues to demonstrate a strong commitment for establishing and operating a disease surveillance programme responsive to the requirements of the International Health Regulations (IHR[2005]). Within five years of its launch, India has effectively used modern information and communication technology for collection, storage, transmission and management of data related to disease surveillance and effective response. Terrestrial and/or satellite based linkages are being established within all states, districts, state-run medical colleges, infectious disease hospitals, and public health laboratories. This network enables speedy data transfer, video conferencing, training and e-learning for outbreaks and programme monitoring. A 24x7 call centre is in operation to receive disease alerts. To complement these efforts, a media scanning and verification cell functions to receive reports of early warning signals. During the 2009 H1N1 outbreak, the usefulness of the information and communication technology (ICT) network was well appreciated. India is using ICT as part of its Integrated Disease Surveillance Project (IDSP) to help overcome the challenges in further expansion in hard-to-reach populations, to increase the involvement of the private sector, and to increase the use of other modes of communication like e-mail and voicemail. PMID:21143821

Kant, Lalit; Krishnan, Sampath K

2010-12-03

66

Terrestrial Ages of Meteorites  

NASA Astrophysics Data System (ADS)

The terrestrial age, or the terrestrial residence time of a meteorite, together with its exposure history provides us with useful insight into the history of the meteorite. It is easy to observe that stony meteorites can weather quickly in humid environments. However, we find that large numbers of meteorites found in semiarid and arid environments can survive for much longer times. Meteorites in desert environments can survive for at least 50,000 yr, and there are some meteorites over 250,000 yr old from these locations. The cold and dry conditions of polar regions such as Antarctica are also good for the storage of meteorites. A considerable number of meteorites survive there for hundreds of thousands of years. Some meteorites have been found in Antarctica with ages of up to 2 m.y. In this paper, we discuss the terrestrial residence times or terrestrial ages of these meteorites. We will show the wide range of terrestrial ages from different environments.

Jull, A. J. T.

67

Are satellite based rainfall estimates accurate enough for crop modelling under Sahelian climate?  

NASA Astrophysics Data System (ADS)

Agriculture is considered as the most climate dependant human activity. In West Africa and especially in the sudano-sahelian zone, rain-fed agriculture - that represents 93% of cultivated areas and is the means of support of 70% of the active population - is highly vulnerable to precipitation variability. To better understand and anticipate climate impacts on agriculture, crop models - that estimate crop yield from climate information (e.g rainfall, temperature, insolation, humidity) - have been developed. These crop models are useful (i) in ex ante analysis to quantify the impact of different strategies implementation - crop management (e.g. choice of varieties, sowing date), crop insurance or medium-range weather forecast - on yields, (ii) for early warning systems and to (iii) assess future food security. Yet, the successful application of these models depends on the accuracy of their climatic drivers. In the sudano-sahelian zone , the quality of precipitation estimations is then a key factor to understand and anticipate climate impacts on agriculture via crop modelling and yield estimations. Different kinds of precipitation estimations can be used. Ground measurements have long-time series but an insufficient network density, a large proportion of missing values, delay in reporting time, and they have limited availability. An answer to these shortcomings may lie in the field of remote sensing that provides satellite-based precipitation estimations. However, satellite-based rainfall estimates (SRFE) are not a direct measurement but rather an estimation of precipitation. Used as an input for crop models, it determines the performance of the simulated yield, hence SRFE require validation. The SARRAH crop model is used to model three different varieties of pearl millet (HKP, MTDO, Souna3) in a square degree centred on 13.5°N and 2.5°E, in Niger. Eight satellite-based rainfall daily products (PERSIANN, CMORPH, TRMM 3b42-RT, GSMAP MKV+, GPCP, TRMM 3b42v6, RFEv2 and EPSAT-SG) are integrated using a crop model, then compared and tested against simulations obtained using in situ data. As in situ data, kriged rain gauge measurements are computed from about 50 rain gauges within the square degree. We show that direct use of SRFE does not reproduce the yield variability obtained from in situ observations. In a second time, different satellite products errors (e.g. annual bias, accuracy at the beginning of the rainy season) are corrected before yield modelling to assess their impact on crop yield simulation and to be able to know which improvement in SRFE will be useful for crop yield estimation. We show that corrected satellite products enable a better yield variability representation and that error correction does not have the same impact on the different varieties computed. Finally, simulated yield quality versus precipitations temporal resolution is assessed - as well as SRFE accuracy versus SRFE temporal resolution - in order to sort out the best agreement between temporal resolution and SRFE accuracy.

Ramarohetra, J.; Sultan, B.

2012-04-01

68

Satellite-based Estimates of Ambient Air Pollution and Global Variations in Childhood Asthma Prevalence  

PubMed Central

Background: The effect of ambient air pollution on global variations and trends in asthma prevalence is unclear. Objectives: Our goal was to investigate community-level associations between asthma prevalence data from the International Study of Asthma and Allergies in Childhood (ISAAC) and satellite-based estimates of particulate matter with aerodynamic diameter < 2.5 µm (PM2.5) and nitrogen dioxide (NO2), and modelled estimates of ozone. Methods: We assigned satellite-based estimates of PM2.5 and NO2 at a spatial resolution of 0.1° × 0.1° and modeled estimates of ozone at a resolution of 1° × 1° to 183 ISAAC centers. We used center-level prevalence of severe asthma as the outcome and multilevel models to adjust for gross national income (GNI) and center- and country-level sex, climate, and population density. We examined associations (adjusting for GNI) between air pollution and asthma prevalence over time in centers with data from ISAAC Phase One (mid-1900s) and Phase Three (2001–2003). Results: For the 13- to 14-year age group (128 centers in 28 countries), the estimated average within-country change in center-level asthma prevalence per 100 children per 10% increase in center-level PM2.5 and NO2 was –0.043 [95% confidence interval (CI): –0.139, 0.053] and 0.017 (95% CI: –0.030, 0.064) respectively. For ozone the estimated change in prevalence per parts per billion by volume was –0.116 (95% CI: –0.234, 0.001). Equivalent results for the 6- to 7-year age group (83 centers in 20 countries), though slightly different, were not significantly positive. For the 13- to 14-year age group, change in center-level asthma prevalence over time per 100 children per 10% increase in PM2.5 from Phase One to Phase Three was –0.139 (95% CI: –0.347, 0.068). The corresponding association with ozone (per ppbV) was –0.171 (95% CI: –0.275, –0.067). Conclusion: In contrast to reports from within-community studies of individuals exposed to traffic pollution, we did not find evidence of a positive association between ambient air pollution and asthma prevalence as measured at the community level.

Butland, Barbara K.; van Donkelaar, Aaron; Brauer, Michael; Strachan, David P.; Clayton, Tadd; van Dingenen, Rita; Amann, Marcus; Brunekreef, Bert; Cohen, Aaron; Dentener, Frank; Lai, Christopher; Lamsal, Lok N.; Martin, Randall V.; One, ISAAC Phase

2012-01-01

69

Efficient all-solid-state UV source for satellite-based lidar applications  

NASA Astrophysics Data System (ADS)

A satellite-based UV-DIAL measurement system would allow continuous global monitoring of ozone concentration in the upper atmosphere. However such systems remain difficult to implement because aerosol-scattering return signals for satellite-based lidars are very weak. A suitable system must produce high-energy UV pulses at multiple wavelengths with very high efficiency. For example, a nanosecond system operating at 10 Hz must generate approximately 1 J per pulse at 308-320 nm. An efficient space-qualified wavelength-agile system based on a single UV source that can meet this requirement is probably not available using current laser technology. As an alternative, we're pursuing a multi-source approach employing all-solid-state modules that individually generate 300-320 nm light with pulse energies in the range of 50-200 mJ, with transform-limited bandwidths and good beam quality. Pulses from the individual sources can be incoherently summed to obtain the required single-pulse energy. These sources use sum-frequency mixing of the 532 nm second harmonic of an Nd:YAG pump laser with 731-803 nm light derived from a recently-developed, state-of-the-art, nanosecond optical parametric oscillator. Two source configurations are under development, one using extra-cavity sum-frequency mixing, and the other intra-cavity sum-frequency mixing. In either configuration, we hope to obtain sum-frequency mixing efficiency approaching 60% by carefully matching the spatial and temporal properties of the laser and OPO pulses. This ideal balance of green and near-IR photons requires an injection-seeded Nd:YAG pump-laser with very high beam quality, and an OPO exhibiting unusually high conversion efficiency and exceptional signal beam quality. The OPO employs a singly-resonant high-Fresnel-number image-rotating self-injection-seeded nonplanar-ring cavity that achieves pump depletion > 65% and produces signal beams with M2 ? 3 at pulse energies exceeding 50 mJ. Pump beam requirements can be met in the laboratory using a commercial Nd:YAG laser system, but only after extensive modifications.

Armstrong, Darrell J.; Smith, Arlee V.

2003-12-01

70

Satellite-Based Distance Courses for In-Service Training: The Case of HeadsUp! Reading  

ERIC Educational Resources Information Center

|This article discusses the use of distance courses as an in-service training mechanism for early childhood personnel. The authors evaluated the efficacy of the in-service, satellite based distance course HeadsUp! Reading (HU!R). The analysis of HU!R data revealed that there were no initial differences in the Language and Literacy Early Childhood:…

Morrison, Johnetta Wade; Raya-Carlton, Pamela; Henk, Jennifer K.; Thornburg, Kathy R.

2007-01-01

71

Satellite-Based Distance Courses for In-Service Training: The Case of HeadsUp! Reading  

ERIC Educational Resources Information Center

This article discusses the use of distance courses as an in-service training mechanism for early childhood personnel. The authors evaluated the efficacy of the in-service, satellite based distance course HeadsUp! Reading (HU!R). The analysis of HU!R data revealed that there were no initial differences in the Language and Literacy Early Childhood:…

Morrison, Johnetta Wade; Raya-Carlton, Pamela; Henk, Jennifer K.; Thornburg, Kathy R.

2007-01-01

72

Interannual response of global ocean hindcasts to a satellite-based correction of precipitation fluxes  

NASA Astrophysics Data System (ADS)

We present a methodology to correct precipitation fluxes from the ECMWF atmospheric reanalysis (ERA-Interim) for oceanographic applications. The correction is performed by means of a spatially varying monthly climatological coefficient, computed within the period 1989-2008 by comparison between ERA-Interim and a satellite-based passive microwave precipitation product. ERA-Interim exhibits a systematic over-estimation of precipitation within the inter-tropical convergence zones (up to 3 mm d-1) and under-estimation at mid- and high- latitudes (up to -4 mm d-1). The correction has been validated within eddy-permitting resolution global ocean hindcasts (1989-2009), demonstrating the ability of our strategy in attenuating the 20-yr mean global EMP negative imbalance by 16%, reducing the near-surface salinity fresh bias in the Tropics up to 1 psu and improving the representation of the sea level interannual variability, with an SSH error decrease of 8%. The ocean circulation is also proved to benefit from the correction, especially in correspondence of the Antarctic Circumpolar Current, where the error in the near-surface current speed decreases by a 9%. Finally, we show that the correction leads to volume and freshwater transports that better agree with independent estimates.

Storto, A.; Russo, I.; Masina, S.

2012-02-01

73

Global long-term passive microwave satellite-based retrievals of vegetation optical depth  

NASA Astrophysics Data System (ADS)

Vegetation optical depth (VOD) retrievals from three satellite-based passive microwave instruments were merged to produce the first long-term global microwave-based vegetation product. The resulting VOD product spans more than two decades and shows seasonal cycles and inter-annual variations that generally correspond with those observed in the Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI). Some notable differences exist in the long-term trends: the NDVI, operating in the optical regime, is sensitive to chlorophyll abundance and photosynthetically active biomass of the leaves, whereas the microwave-based VOD is an indicator of the vegetation water content in total above-ground biomass, i.e., including wood and leaf components. Preliminary analyses indicate that the fluctuations in VOD typically correlated to precipitation variations, and that the mutually independent VOD and NDVI do not necessarily respond in identical manners. Considering both products together provides a more robust structural characterization and assessment of long-term vegetation dynamics at the global scale.

Liu, Yi Y.; de Jeu, Richard A. M.; McCabe, Matthew F.; Evans, Jason P.; van Dijk, Albert I. J. M.

2011-09-01

74

Intrusion of coastal waters into the pelagic eastern Mediterranean: in situ and satellite-based characterization  

NASA Astrophysics Data System (ADS)

A combined dataset of near-real-time multi-satellite observations and in situ measurements from a high-resolution survey is used for characterizing physical-biogeochemical properties of a patch stretching from the coast to the open sea in the Levantine Basin (LB) of the eastern Mediterranean (EM). Spatial analysis of the combined dataset indicates that the patch is a semi-enclosed system, bounded within the mixed layer and separated from ambient waters by transport barriers induced by horizontal stirring. As such, the patch is characterized by physical-biogeochemical properties that significantly differ from those of the waters surrounding it, with lower salinity and higher temperatures, concentrations of silicic acid and chlorophyll a, and abundance of Synechococcus and picoeukaryote cells. Based on estimates of patch dimensions (∼40 km width and ∼25 m depth) and propagation speed (∼0.09 m s-1), the volume flux associated with the patch is found to be on the order of 0.1 Sv. Our observations suggest that horizontal stirring by surface currents is likely to have an important impact on the ultra-oligotrophic Levantine Basin ecosystem, through (1) transport of nutrients and coastally derived material, and (2) formation of local, dynamically isolated niches. In addition, this work provides a satellite-based framework for planning and executing high-resolution sampling strategies in the interface between the coast and the open sea.

Efrati, S.; Lehahn, Y.; Rahav, E.; Kress, N.; Herut, B.; Gertman, I.; Goldman, R.; Ozer, T.; Lazar, M.; Heifetz, E.

2013-05-01

75

National satellite-based land-use regression: NO2 in the United States.  

PubMed

Land-use regression models (LUR) estimate outdoor air pollution at high spatial resolution. Previous LURs have generally focused on individual cities. Here, we present an LUR for year-2006 ground-level NO(2) concentrations throughout the contiguous United States. Our approach employs ground- and satellite-based NO(2) measurements, and geographic characteristics such as population density, land-use (based on satellite data), and distance to major and minor roads. The results provide reliable estimates of ambient NO(2) air pollution as measured by the U.S. EPA (R(2) = 0.78; bias = 22%) at a spatial resolution (? 30 m) that is capable of capturing within-urban and near-roadway gradients in NO(2). We explore several aspects of temporal (time-of-day; day-of-week; season) and spatial (urban versus rural; U.S. region) variability in the model. Results are robust to spatial autocorrelation, to selection of an alternative input data set, and to minor perturbations in input data (using 90% of the data to predict the remaining 10%). The modeled population-weighted (unweighted) mean outdoor concentration in the United States is 10.7 (4.8) ppb. Our approach could be implemented in other areas of the world given sufficient road network and pollutant monitoring data. To facilitate future use and evaluation of the results, concentration estimates for the ? 8 million U.S. Census blocks in the contiguous United States are publicly available via the Supporting Information. PMID:21520942

Novotny, Eric V; Bechle, Matthew J; Millet, Dylan B; Marshall, Julian D

2011-04-26

76

New satellite-based maps of the growing season north of 50°N  

NASA Astrophysics Data System (ADS)

In this study we present new satellite-based maps of the growing season of northern areas. The maps show trends and mean date in onset and length of the growing season at different scales north of 50° N. For all the circumpolar area we use the GIMMS-NDVI satellite dataset for the 1982 to 2006 period, and for the Nordic countries we used the MODISNDVI satellite data for the 2000 to 2007 period. The circumpolar maps are not as accurate as the one covering the Nordic countries, this due to lack of ancillary environmental geo-data available that can be included in the mapping process. In particular this is a problem for the Russian part of the circumpolar north. The resulting growing season maps are useful in a broad range of ecological and climatic changes studies. Changes in the timing of the growing season are sensitive bio-indicators of climate change of northern areas, and these changes crucially affects primary industries, such as agriculture, animal husbandry and forestry, as well as the population dynamics of wild mammals and birds. The onset of growing season maps is also useful to improve pollen forecasts, and the maps can be used to improve the global change models.

Rune Karlsen, Stein; Arild Høgda, Kjell; Tolvanen, Anne; Johansen, Bernt; Elvebakk, Arve

2009-09-01

77

Terrestrial and Extraterrestrial Fullerenes  

Microsoft Academic Search

This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous?Tertiary?Boundary and Permian?Triassic?Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated

D. Heymann; L. W. Jenneskens; J. Jehli?ka; Carola Koper; E. J. Vlietstra

2003-01-01

78

Advances In Global Aerosol Modeling Applications Through Assimilation of Satellite-Based Lidar Measurements  

NASA Astrophysics Data System (ADS)

Modeling the instantaneous three-dimensional aerosol field and its downwind transport represents an endeavor with many practical benefits foreseeable to air quality, aviation, military and science agencies. The recent proliferation of multi-spectral active and passive satellite-based instruments measuring aerosol physical properties has served as an opportunity to develop and refine the techniques necessary to make such numerical modeling applications possible. Spurred by high-resolution global mapping of aerosol source regions, and combined with novel multivariate data assimilation techniques designed to consider these new data streams, operational forecasts of visibility and aerosol optical depths are now available in near real-time1. Active satellite-based aerosol profiling, accomplished using lidar instruments, represents a critical element for accurate analysis and transport modeling. Aerosol source functions, alone, can be limited in representing the macrophysical structure of injection scenarios within a model. Two-dimensional variational (2D-VAR; x, y) assimilation of aerosol optical depth from passive satellite observations significantly improves the analysis of the initial state. However, this procedure can not fully compensate for any potential vertical redistribution of mass required at the innovation step. The expense of an inaccurate vertical analysis of aerosol structure is corresponding errors downwind, since trajectory paths within successive forecast runs will likely diverge with height. In this paper, the application of a newly-designed system for 3D-VAR (x,y,z) assimilation of vertical aerosol extinction profiles derived from elastic-scattering lidar measurements is described [Campbell et al., 2009]. Performance is evaluated for use with the U. S. Navy Aerosol Analysis and Prediction System (NAAPS) by assimilating NASA/CNES satellite-borne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) 0.532 ?m measurements [Winker et al., 2009]. Inversion retrievals of aerosol extinction are performed for one-degree latitudinal averages of CALIOP backscatter signal (thus matching the horizontal resolution of NAAPS) by constraining total column transmission using the model estimate of AOD at the corresponding wavelength. As such, this system serves as a post-processing module predicated on newly-operational NAAPS aerosol analysis fields that feature 2D-VAR assimilation of NASA Moderate Resolution Infrared Spectroradiometer (MODIS) AOD observations [Zhang and Reid, 2006; Zhang et al., 2008]. We describe the influence of 3D-VAR assimilation on NAAPS analyses and forecasts by considering the physical evolution of Saharan dust plumes during their advection across the tropical Atlantic basin. Steps taken towards characterizing spatial covariance parameters that broaden the horizontal influence of information obtained along the limited lidar orbital swath are discussed. This latter context is critical when comparing the efficacy and impact of 3D-VAR assimilation with that of 2D-VAR procedures, which benefit from passive observations with a relatively wide field-of-view and, therefore, greater/more routine global coverage. With multiple satellite-lidar projects either pending launch or in design stages, including the dual ESA missions (AEOLUS and EarthCARE), we describe the potential impact of future 3D-VAR assimilation activities; both for NAAPS forecast capabilities, and the anticipated growth in aerosol transport modeling efforts at federal and cooperative global agencies worldwide. 1 http://www.nrlmry.navy.mil/aerosol/ References Campbell, J. R., J. S. Reid, D. L. Westphal, J. Zhang, E. J. Hyer, and E. J. Welton, CALIOP aerosol subset processing for global aerosol transport model data assimilation, in press, J. Selected Topics Appl. Earth Obs. Rem. Sens., December 2009. Winker, D. M., M. A. Vaughan, A. Omar, Y. Hu, K. A. Powell, Z. Liu, W. H. Hunt, and S. A. Young, Overview of the CALIPSO mission and CALIOP data processing algorithms, J. Atmos. Oceanic. Technol., 26, DOI:10.1175/2009JTECHA1281.1, 2009. Zhang,

Campbell, James; Hyer, Edward; Zhang, Jianglong; Reid, Jeffrey; Westphal, Douglas; Xian, Peng; Vaughan, Mark

2010-05-01

79

Validation of satellite-based precipitation estimates over different African River Basins  

NASA Astrophysics Data System (ADS)

Satellite-based precipitation products have become increasingly available and accessible in near real-time, encouraging the scientific community increasingly to use these data to replace or supplement sparse ground observations. Six satellite-based rainfall estimates (SRFE), namely, CMORPH, RFE 2.0, TRMM 3B42, GPROF 6.0, PERSIANN, GSMaP-MKV, and one reanalysis product (ERA-interim) are validated against rain gauge data over four partly sparsely-gauged African river basins (Zambezi, Volta, Juba-Shabelle and Baro-Akobo). The objective is to provide the scientific community using SRFE as input data for hydro-meteorological applications an intercomparable validation study of these products over different hydro-climatological conditions in Africa. The validation focuses on the general ability of the SRFE products to reproduce daily and monthly rainfall and, particularly, on rainfall characteristics that are relevant to hydro-meteorological applications, such as, annual catchment totals, spatial distribution pattern within the river basin, seasonality of precipitation, number of rainy days per year, and timing and amount of heavy rainfall events. The accuracy of those products is assessed using a ground observation network, comprising of 203 stations with daily records between 2003 and 2006 (data coverage: <25, 25- 50, 50-75 and >75 % of data for 38, 13, 18 and 31 % of stations, respectively). Considering the time and space variability of the different rainfall characteristics as well as the conventional hydrological working units, the validation is done on three spatially-aggregated levels: point, subcatchment, and river basin. For the latter two the ground observations are interpolated using Kriging with External Drift, where the drift is defined as the terrain elevation. The performance is measured using standard statistical measures (MAE, RMSE, pBIAS, r, and NSeff) as well as visual inspection. The examined products showed depending on the spatially-aggregated level they have been analyzed: a) a good reproduction of dry periods, b) skills in reproducing precipitation over arid areas on a monthly basis, c) good representation of the spatial distribution pattern across the basins, d) difficulties in capturing the amount of precipitation on an event basis, and e) low detectability of heavy rainfall events over mountainous areas. Product-wise, GPROF 6.0 and GSMaP-MKV exhibited the poorest performance, which might be linked to the interpolation that was required due to the not complete daily coverage of the target areas and shortcomings in the algorithm selecting the correct rain profile, respectively. On the contrary, RFE 2.0 and TRMM 3B42 showed the highest potential in reproducing the inter-annual variability, the spatial and quantitative distribution, and the timing of rainfall events and, thus, may be recommendable as input for hydro-meteorological applications on a pan-African scale, such as monitoring and forecasting of floods and droughts.

Thiemig, V.; Rojas, R.; Levizzani, V.; De Roo, A.

2012-04-01

80

Categorizing natural disaster damage assessment using satellite-based geospatial techniques  

USGS Publications Warehouse

Remote sensing of a natural disaster's damage offers an exciting backup and/or alternative to traditional means of on-site damage assessment. Although necessary for complete assessment of damage areas, ground-based damage surveys conducted in the aftermath of natural hazard passage can sometimes be potentially complicated due to on-site difficulties (e.g., interaction with various authorities and emergency services) and hazards (e.g., downed power lines, gas lines, etc.), the need for rapid mobilization (particularly for remote locations), and the increasing cost of rapid physical transportation of manpower and equipment. Satellite image analysis, because of its global ubiquity, its ability for repeated independent analysis, and, as we demonstrate here, its ability to verify on-site damage assessment provides an interesting new perspective and investigative aide to researchers. Using one of the strongest tornado events in US history, the 3 May 1999 Oklahoma City Tornado, as a case example, we digitized the tornado damage path and co-registered the damage path using pre- and post-Landsat Thematic Mapper image data to perform a damage assessment. We employed several geospatial approaches, specifically the Getis index, Geary's C, and two lacunarity approaches to categorize damage characteristics according to the original Fujita tornado damage scale (F-scale). Our results indicate strong relationships between spatial indices computed within a local window and tornado F-scale damage categories identified through the ground survey. Consequently, linear regression models, even incorporating just a single band, appear effective in identifying F-scale damage categories using satellite imagery. This study demonstrates that satellite-based geospatial techniques can effectively add spatial perspectives to natural disaster damages, and in particular for this case study, tornado damages.

Myint, S. W.; Yuan, M.; Cerveny, R. S.; Giri, C.

2008-01-01

81

Satellite-based overshooting top detection methods and an analysis of correlated weather conditions  

NASA Astrophysics Data System (ADS)

The paper addresses two topics: the possibilities of satellite-based automatic detection of overshooting convective cloud tops and the connection between the overshootings and the occurrence of severe weather on the ground. Because the use of visible images is restricted to daytime, four detection methods based on the Meteosat Second Generation SEVIRI 10.8 ?m infra-red window channel and the absorption channels of water vapor (6.2 ?m), ozone (9.7 ?m) and carbon dioxide (13.4 ?m) in the form of brightness temperature differences were used. The theoretical background of all four methods is explained, and the detection results are compared with daytime high-resolution visible (HRV) satellite images to validate each method. Of the four tested methods, the best performance is found for the combination of brightness temperature differences 6.2-10.8 and 9.7-10.8 ?m, which are correlated to overshootings in HRV images in 80% of the cases.The second part of the research is focused on determining whether the appearance of the overshooting top, a manifestation of a very strong updraft in the cloud, can be connected to an abrupt change of certain weather elements on the ground. For all overshooting tops found by the above-mentioned combined method, automatic station data within the range of 0.1° and available hail observations within 0.2° were analyzed. The results show that the overshootings are connected to precipitation in 80% and to wind gusts in 70% of the cases; in contrast, a slightly lower correlation was found for temperature and humidity changes. Hail is observed in the vicinity of the overshooting in 38% of the cases.

Mikuš, Petra; Strelec Mahovi?, Nataša

2013-04-01

82

Comparison of Historical Satellite-Based Estimates of Solar Radiation Resources with Recent Rotating Shadowband Radiometer Measurements: Preprint  

SciTech Connect

The availability of rotating shadow band radiometer measurement data at several new stations provides an opportunity to compare historical satellite-based estimates of solar resources with measurements. We compare mean monthly daily total (MMDT) solar radiation data from eight years of NSRDB and 22 years of NASA hourly global horizontal and direct beam solar estimates with measured data from three stations, collected after the end of the available resource estimates.

Myers, D. R.

2009-03-01

83

Hazard assessment at Mount Etna using a hybrid lava flow inundation model and satellite-based land classification  

Microsoft Academic Search

Using a lava flow emplacement model and a satellite-based land cover classification, we produce a map to allow assessment\\u000a of the type and quantity of natural, agricultural and urban land cover at risk from lava flow invasion. The first step is\\u000a to produce lava effusion rate contours, i.e., lines linking distances down a volcano’s flank that a lava flow will

Andrew J. L. HarrisMassimiliano; Massimiliano Favalli; Robert Wright; Harold Garbeil

2011-01-01

84

Satellite-based agroclimatic indicators to support real-time and strategic decisions in agricultural management  

NASA Astrophysics Data System (ADS)

The objective of the poster is to present our activity in the COST-734 Action, CLIVAGRI of collection of satellite based information on the actual state and longer-term evolution of vegetation cover. The main purpose of CLIVAGRI is the evaluation of possible impacts from climate change and variability on agriculture and the assessment of critical thresholds for various European areas. As one of its targets, sensitivity, adaptive capacity and vulnerability of European agriculture areas are evaluated to provide users with all the information needed to adapt their strategies to current and future climatic conditions. This covers the fields of farmer activity, public and private extension services and especially policy-maker decisions on short- and long-term bases. Under a changing climate, the role of agriculture as provider of environmental and ecosystem services will gain further importance. These services rely more and more on remotely sensed information, mainly gathered from meteorological and land surface imaging satellites. Satellite-derived variables already have a long record of monitoring crop production. The most relevant variables measured over land are: solar radiation, albedo, vegetation indices, leaf area index (LAI), land surface temperature (LST), rainfall, fires and burned area, snow cover and land use types. Some of these variables are required as inputs to give an immediate view of climate change impact for example. The most important parameters of this type are: vegetation indices and specifically the normalised difference vegetation index (NDVI), maximum and total greenness during the growing season, fraction of Photosynthetically Active Radiation and its absorbed proportion (FPAR and APAR) and the leaf area index (LAI). The present aim of the specific Working Group within the COST-734 is to prepare an intelligent inventory of the practically available agroclimatic indicators and to provide them together with general recommendations for their use, together with practical case studies. The results will be disseminated in order to significantly enhance awareness in the agricultural sector of the current hazard level and the perspectives related to the next few decades. Risk maps, graphics, tables, etc. will be used to provide the requested information to end-users. The current state of these activities will be displayed through this poster.

Toulios, L.; Mika, J.; Struzik, P.; Tsiros, E.; Dunkel, Z.; Stancalie, G.; Danson, F. M.

2009-04-01

85

Satellite-based PM concentrations and their application to COPD in Cleveland, OH.  

PubMed

A hybrid approach is proposed to estimate exposure to fine particulate matter (PM2.5) at a given location and time. This approach builds on satellite-based aerosol optical depth (AOD), air pollution data from sparsely distributed Environmental Protection Agency (EPA) sites and local time-space Kriging, an optimal interpolation technique. Given the daily global coverage of AOD data, we can develop daily estimate of air quality at any given location and time. This can assure unprecedented spatial coverage, needed for air quality surveillance and management and epidemiological studies. In this paper, we developed an empirical relationship between the 2?km AOD and PM2.5 data from EPA sites. Extrapolating this relationship to the study domain resulted in 2.3 million predictions of PM2.5 between 2000 and 2009 in Cleveland Metropolitan Statistical Area (MSA). We have developed local time-space Kriging to compute exposure at a given location and time using the predicted PM2.5. Daily estimates of PM2.5 were developed for Cleveland MSA between 2000 and 2009 at 2.5?km spatial resolution; 1.7?million (?79.8%) of 2.13?million predictions required for multiyear and geographic domain were robust. In the epidemiological application of the hybrid approach, admissions for an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) was examined with respect to time-space lagged PM2.5 exposure. Our analysis suggests that the risk of AECOPD increases 2.3% with a unit increase in PM2.5 exposure within 9 days and 0.05° (?5?km) distance lags. In the aggregated analysis, the exposed groups (who experienced exposure to PM2.5 >15.4??g/m(3)) were 54% more likely to be admitted for AECOPD than the reference group. The hybrid approach offers greater spatiotemporal coverage and reliable characterization of ambient concentration than conventional in situ monitoring-based approaches. Thus, this approach can potentially reduce exposure misclassification errors in the conventional air pollution epidemiology studies. PMID:24045428

Kumar, Naresh; Liang, Dong; Comellas, Alejandro; Chu, Allen D; Abrams, Thad

2013-09-18

86

The development of potassium tantalate niobate thin films for satellite-based pyroelectric detectors  

SciTech Connect

Potassium tantalate niobate (KTN) pyroelectric detectors are expected to provide detectivities, of 3.7 x 10{sup 11} cmHz {sup {1/2}}W{sup {minus}1} for satellite-based infrared detection at 90 K. The background limited detectivity for a room-temperature thermal detector is 1.8 x 10{sup 10} cmHz{sup {1/2}}W{sup {minus}1}. KTN is a unique ferroelectric for this application because of the ability to tailor the temperature of its pyroelectric response by adjusting its ratio of tantalum to niobium. The ability to fabricate high quality KTN thin films on Si-based substrates is crucial to the development of KTN pyroelectric detectors. Si{sub x}N{sub y} membranes created on the Si substrate will provide the weak thermal link necessary to reach background limited detectivities. The device dimensions obtainable by thin film processing are expected to increase the ferroelectric response by 20 times over bulk fabricated KTN detectors. In addition, microfabrication techniques allow for easier array development. This is the first reported attempt at growth of KTN films on Si-based substrates. Pure phase perovskite films were grown by pulsed laser deposition on SrRuO{sub 3}/Pt/Ti/Si{sub x}N{sub y}/Si and SrRuO{sub 3}/Si{sub x}N{sub y}/Si structures; room temperature dielectric permittivities for the KTN films were 290 and 2.5, respectively. The dielectric permittivity for bulk grown, single crystal KTN is {approximately}380. In addition to depressed dielectric permittivities, no ferroelectric hysteresis was found between 80 and 300 K for either structure. RBS, AES, TEM and multi-frequency dielectric measurements were used to investigate the origin of this apparent lack of ferroelectricity. Other issues addressed by this dissertation include: the role of oxygen and target density during pulsed laser deposition of KTN thin films; the use of YBCO, LSC and Pt as direct contact bottom electrodes to the KTN films, and the adhesion of the bottom electrode layers to Si{sub x}N{sub y}/Si.

Cherry, H.B.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley National Lab., CA (United States)

1997-05-01

87

The development of potassium tantalate niobate thin films for satellite-based pyroelectric detectors  

NASA Astrophysics Data System (ADS)

Potassium tantalate niobate (KTN) pyroelectric detectors are expected to provide detectivities of 3.7× 10sp{11}\\ cmHzsp{1/2}Wsp{-1} for satellite-based infrared detection at 90 K. The background limited detectivity for a room-temperature thermal detector is 1.8× 10sp{10}\\ cmHzsp{1/2}Wsp{-1}. KTN is a unique ferroelectric for this application because of the ability to tailor the temperature of its pyroelectric response by adjusting its ratio of tantalum to niobium. The ability to fabricate high quality KTN thin films on Si-based substrates is crucial to the development of KTN pyroelectric detectors. Sisb{x}Nsb{y} membranes created on the Si substrate will provide the weak thermal link necessary to reach background limited detectivities. The device dimensions obtainable by thin film processing are expected to increase the ferroelectric response by 20 times over bulk fabricated KTN detectors. In addition, microfabrication techniques allow for easier array development. This is the first reported attempt at growth of KTN films on Si-based substrates. Pure phase perovskite films were grown by pulsed laser deposition on SrRuOsb3/Pt/Ti/Sisb{x}Nsb{y}/Si and SrRuOsb3/Sisb{x}Nsb{y}/Si structures; room temperature dielectric permittivities for the KTN films were 290 and 2.5, respectively. The dielectric permittivity for bulk grown, single crystal KTN is {˜}380. In addition to depressed dielectric permittivities, no ferroelectric hysteresis was found between 80 and 300 K for either structure. RBS, AES, TEM and multi-frequency dielectric measurements were used to investigate the origin of this apparent lack of ferroelectricity. The most likely explanation is the presence of point defects. Other issues addressed by this dissertation include: the role of oxygen and target density during pulsed laser deposition of KTN thin films; the use of YBCO, LSC and Pt as direct contact bottom electrodes to the KTN films, the adhesion of the bottom electrode layers to Sisb{x}Nsb{y}/Si and the top electrode adhesion.

Cherry, Hilary Beatrix Baumann

88

Structural Interrelationships between Evaporation and Precipitation: Application of Complex Networks to Satellite based Fields  

NASA Astrophysics Data System (ADS)

Constantly growing amount of scientific questions and tasks demands exploitation of new analytical and interpretational strategies. The novel method of complex climate networks (CCN) opened new perspectives in climate research through its idea of decomposition a system of interactions to simpler structural dependencies. Application of the CCN method to satellite and model based evaporation (E) and precipitation (P) fields in the study was aimed to answer three global questions: What are the structural properties of satellite based E and P fields at monthly and annual time scales and what do they represent? What is the system of interactions between E and P over the ocean and how stable they are with time? How biases in model simulated parameters of E and P are mirrored in their network structure, thus addressing the question of model evaluation using the method of CCN? To construct single and coupled networks 13- year time-series (1992-2005) of E and P was retrieved from the Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data (HOAPS-3) data set and the Earth System Model of the Max-Planck-Institute for Meteorology (MPI-ESM), conducted in the frame of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Two experimental setups of the MPI-ESM using either a full coupled climate model (ocean, atmosphere, land) or prescribed sea surface temperature fields (atmosphere, land only) were utilized. Analyzed topology of single and coupled E and P networks revealed most prominent ENSO and NAO driven (co-) variability areas over the global and North Atlantic domains correspondingly. Identified topological features, and especially in the (cros-)degree measure, showed high correlation to the first mode of the EOF (single) and SVD (coupled) analysis. Comparison to the MPI-ESM based E and P networks demonstrated higher similarity to the fully coupled experiment based networks. Single and coupled networks of the latter quite well reproduced ENSO and NAO teleconnections correspondingly. This emphasizes again the importance of improvement of simulation responses of SST to related parameters as well as other coupled dynamical feedbacks.

Petrova, Irina; Löw, Alexander; Kurths, Jürgen

2013-04-01

89

Diterpenoids of terrestrial origin.  

PubMed

Covering January to December 2012. Previous review, Nat.Prod.Rep., 2012, 29, 890-898.This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes labdanes, clerodanes, abietanes, pimaranes, kauranes, cembranes and their cyclization products. There are 169 references. PMID:23942594

Hanson, James R

2013-08-13

90

Terrestrial carbon sequestration potential  

Microsoft Academic Search

Fossil fuel use and land use change that began over 200 years ago are driving the rapid increase in atmospheric content of CO2 and other greenhouse gases that may be impacting on climatic change. Enhanced terrestrial uptake of CO2 over the next 50 to 100 years has been suggested as a way to reclaim the 150 or more Pg carbon

METTING Blaine

91

Upwelling Terrestrial Radiation  

NSDL National Science Digital Library

The Stefan-Boltzmann Law is a fundamental law of physics. In this lesson, students will use this law and the near-ground air temperature to compute the hourly irradiance emitted by the surface of Earth. Then comparisons will be made with actual observations of this variable, called upwelling terrestrial radiation.

92

Altitudinal terrestrial isopod diversity  

Microsoft Academic Search

We have assessed the diversity of terrestrial isopods across an elevational and habitat gradient on Mt. Panachaiko (NW Peloponnisos, Greece). Previous knowledge on the biodiversity of this mountain was restricted to very few records of individual species, and no systematic sampling had ever been applied for any animal taxon. We selected the most representative habitat types within an altitudinal range

Spyros Sfenthourakis; Ioannis Anastasiou; Theodora Strutenschi

2005-01-01

93

Terrestrial planet formation  

PubMed Central

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (?106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Righter, K.; O'Brien, D. P.

2011-01-01

94

The scheme for integration of satellite-based C4ISR system  

NASA Astrophysics Data System (ADS)

This paper presents a technical scheme for the integrating of all types of strategic and tactical C4ISR systems through special satellite communication network and proposes information collection and distribution integrating networking scheme. The implementations of compatibility and interoperability of integrated system is described, and also anti-jamming features, covertness, and nuclear survivability are discussed.

Chen, Zhenyu; Meng, Yan; Chen, Yanhong

2005-11-01

95

Arsenic Speciation of Terrestrial Invertebrates  

Microsoft Academic Search

The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine

Maeve M. Moriarty; Iris Koch; Robert A. Gordon; Kenneth J. Reimer

2009-01-01

96

A Hierarchy Management Framework for LEO Satellite Communication Networks  

Microsoft Academic Search

An autonomous iteration-based approach is proposed to identify faulty links for LEO satellite systems employing intersatellite links (ISLpsilas). A designed network satellite with management responsibilities collects the routing information of communication itself with other satellites, based on which a fault diagnosis model is introduced. Then the most likely faulty link is identified by using an iteration-based probability method, in conjunction

Zhi-Gang Zhao; Jian-Hui Wang

2008-01-01

97

Optical satellite communications in Europe  

NASA Astrophysics Data System (ADS)

This paper describes optical satellite communication activities based on technology developments, which started in Europe more than 30 years ago and led in 2001 to the world-first optical inter-satellite communication link experiment (SILEX). SILEX proved that optical communication technologies can be reliably mastered in space and in 2006 the Japanese Space Agency (JAXA) joined the optical inter-satellite experiment from their own satellite. Since 2008 the German Space Agency (DLR) is operating an inter-satellite link between the NFIRE and TerraSAR-X satellites based on a second generation of laser communication technology, which will be used for the new European Data Relay Satellite (EDRS) system to be deployed in 2013.

Sodnik, Zoran; Lutz, Hanspeter; Furch, Bernhard; Meyer, Rolf

2010-02-01

98

Integrating ground-based EO data in satellite-based systems  

SciTech Connect

Earth observation (EO) and other forms of geo-referenced data are typically thought of as being ``satellite data.`` It is true that the majority of EO data are satellite oriented; thus, most on-line EO data systems are designed primarily for satellite image data. However, there is A small but significant minority of EO data that is not satellite image data; i.e., it is ground-based or terrestrial data Unfortunately, many on-line systems designed for satellite data do not take into account the somewhat different nature of associated ground-based data, Data queries that work most of the time but fail because the system has not taken into account less common data are not robust enough for today`s users. In order to avoid embarrassing problems, EO system designers must be aware of the nature of ground- based data. In this paper we describe some of our insights on this subject in the hope that the designers of other systems may learn from our experience.

Jennings, S.V.; Daugherty, P.; Yow, T.G.

1997-02-01

99

Satellite-based Estimates of Surface and Groundwater Storage Variations in the Amazon Basin  

NASA Astrophysics Data System (ADS)

The Amazon river basin has been recently affected by extreme climatic events, such as the exceptional drought of 2005, with signi?cant impacts on human activities and ecosystems. In spite of the importance of monitoring freshwater stored and moving in such large river basins, only scarce measurements of river stages and discharges are available and the signatures of extreme drought conditions on surface freshwater dynamics at the basin scale are still poorly known. Here we use continuous multisatellite observations of inundation extent and water levels between 2003 and 2007 to monitor monthly variations of surface water storage at the basin scale. During the 2005 drought, the amount of water stored in the river and ?oodplains of the Amazon basin was ˜130 km3 (˜70%) below its 2003-7 average. This represents almost a half of the anomaly of minimum terrestrial water stored in the basin as estimated using the Gravity Recovery and Climate Experiment (GRACE) data. Water stored in the aquifer is isolated from the total water storage measured by GRACE by removing the contributions of both the surface reservoir, previously derived from satellite imagery and radar altimetry, and the root zone reservoir simulated by hydrological models such as LaD and WGHM. The spatio-temporal variations of surface and groundwater reservoirs are compared to other hydrological datasets (i.e., rainfall from TRMM or GPCP, discharges, ...) and analyzed at subbasin scale in the context of the climate variability and recent extreme events such as the drought of 2005.

Frappart, Frédéric; Papa, Fabrice; Santos da Silva, Joecila; Ramillien, Guillaume; Prigent, Catherine; Seyler, Frédérique; Calmant, Stéphane

2013-04-01

100

A unified approach for channel modeling of terrestrial FSO links  

Microsoft Academic Search

Channel modeling for Free Space Optical (FSO) links remain an interesting research problem for the optical wireless community. Major link attenuators for FSO include fog, rain, snow, clouds, turbulence and ambient light. The article reviews the major link attenuators and proposes a novel technique for modeling fog attenuation, which by far is the most detrimental for terrestrial FSO communications. The

Sheikh Sajid Muhammad

2010-01-01

101

International Conference on Satellite Systems for Mobile Communications and Navigation, 4th, London, England, Oct. 17-19, 1988, Proceedings  

NASA Astrophysics Data System (ADS)

Attention is given to the following topics: antennas and propagation, systems for communication, systems for land mobile communications, systems for aeronautical communications, and system economics, operation, and traffic. Particular papers are presented on tracking receiver design for the electronic beam squint tracking system in the maritime mobile environment, network signalling system design considerations in a multiservice mobile satellite communication systems, Inmarsat's aeronautical satellite communication system, and proposed systems configurations for a satellite-based ISDN.

102

High-resolution satellite-based cloud-coupled estimates of total downwelling surface radiation for hydrologic modelling applications  

NASA Astrophysics Data System (ADS)

A relatively simple satellite-based radiation model yielding high-resolution (in space and time) downwelling longwave and shortwave radiative fluxes at the Earth's surface is presented. The primary aim of the approach is to provide a basis for deriving physically consistent forcing fields for distributed hydrologic models using satellite-based remote sensing data. The physically-based downwelling radiation model utilises satellite inputs from both geostationary and polar-orbiting platforms and requires only satellite-based inputs except that of a climatological lookup table derived from a regional climate model. Comparison against ground-based measurements over a 14-month simulation period in the Southern Great Plains of the United States demonstrates the ability to reproduce radiative fluxes at 4 km/h resolution with good accuracy during all-sky conditions. For hourly fluxes, a mean difference of -2 W m-2 with a root mean square difference of 21 W m-2 was found for the longwave fluxes whereas a mean difference of -7 W m-2 with a root mean square difference of 29 W m-2 was found for the shortwave fluxes. Additionally, comparison against advanced downwelling longwave and solar insolation products during all-sky conditions showed comparable uncertainty in the longwave estimates and reduced uncertainty in the shortwave estimates. The relatively simple form of the model enables future usage in ensemble-based applications including data assimilation frameworks in order to explicitly account for input uncertainties while providing the potential for conditioning estimates from other readily available products derived from more sophisticated retrieval algorithms.

Forman, B. A.; Margulis, S. A.

2009-04-01

103

High-resolution satellite-based cloud-coupled estimates of total downwelling surface radiation for hydrologic modelling applications  

NASA Astrophysics Data System (ADS)

A relatively simple satellite-based radiation model yielding high-resolution (in space and time) downwelling longwave and shortwave radiative fluxes at the Earth's surface is presented. The primary aim of the approach is to provide a basis for deriving physically consistent forcing fields for distributed hydrologic models using satellite-based remote sensing data. The physically-based downwelling radiation model utilises satellite inputs from both geostationary and polar-orbiting platforms and requires only satellite-based inputs except that of a climatological lookup table derived from a regional climate model. Comparison against ground-based measurements over a 14-month simulation period in the Southern Great Plains of the United States demonstrates the ability to reproduce radiative fluxes at a spatial resolution of 4 km and a temporal resolution of 1 h with good accuracy during all-sky conditions. For hourly fluxes, a mean difference of -2 W m-2 with a root mean square difference of 21 W m-2 was found for the longwave fluxes whereas a mean difference of -7 W m-2 with a root mean square difference of 29 W m-2 was found for the shortwave fluxes. Additionally, comparison against advanced downwelling longwave and solar insolation products during all-sky conditions showed comparable uncertainty in the longwave estimates and reduced uncertainty in the shortwave estimates. The relatively simple form of the model enables future usage in ensemble-based applications including data assimilation frameworks in order to explicitly account for input uncertainties while providing the potential for conditioning estimates from other readily available products derived from more sophisticated retrieval algorithms.

Forman, B. A.; Margulis, S. A.

2009-07-01

104

Global Communications Infrastructure: CTBT Treaty monitoring using space communications  

NASA Astrophysics Data System (ADS)

Article 1 on Basic Obligations of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) states that: "Each State Party undertakes not to carry out any nuclear weapon test explosion or any other nuclear explosion, and to prohibit and prevent any such nuclear explosion at any place under its jurisdiction or control. Each State Party undertakes, furthermore, to refrain from causing, encouraging, or in any way participating in the carrying out of any nuclear weapon test explosion or any other nuclear explosion." To monitor States Parties compliance with these Treaty provisions, an International Monitoring System (IMS) consisting of 321 monitoring stations and 16 laboratories in some 91 countries is being implemented to cover the whole globe, including its oceans and polar regions. The IMS employs four technologies--seismic, hydroacoustic, infrasound and radionuclide--to detect,locate and identify any seismic event of Richter magnitude 4 and above (equivalent to one kiloton of TNT) that may be associated with a nuclear test explosion. About one-half of this monitoring system is now operational in 67 countries. Monitoring stations send data in near real-time to an International Data Centre (IDC) in Vienna over a Global Communications Infrastructure (GCI) incorporating 10 geostationary satellites plus three satellites in inclined orbits. The satellites relay the data to commercial earth stations, from where they are transferred by terrestrial circuits to the IDC. The IDC automatically processes and interactively analyzes the monitoring data, and distributes the raw data and reports relevant to Treaty verification to National Data Centers in Member States over the same communications network. The GCI will eventually support about 250 thin route VSAT links to the monitoring stations, many of them at remote or harsh locations on the earth, plus additional links to national data centres in various countries. Off-the-shelf VSAT and networking hardware are deployed. This is the first global integrated satellite communications network based on VSAT technology. Space segment has been leased to carry more than 9 gigabytes/day of data to the IDC with a designed annual availability of 99.5%. This paper explains the topology of this satellite-based network, and practical limitations encountered in organizing a single network with 250 links that span the majority of countries in the world, plus the Antarctic regions and the earth's oceans. Having now installed about half of the satellite links in 67 countries, CTBTO has had to hurdle regulatory challenges to install VSAT equipment, and operational challenges to keep the earth stations running in unmanned remote locations. Despite the challenges, the GCI has proven its worth in reliably collecting monitoring data and making such available to authorized users. It has also been useful to give scientists real-time access for controlling their remote monitoring stations.

Kebeasy, R.; Abaya, E.; Ricker, R.; Demeules, G.

105

A comprehensive design and performance analysis of low Earth orbit satellite quantum communication  

NASA Astrophysics Data System (ADS)

Optical quantum communication utilizing satellite platforms has the potential to extend the reach of quantum key distribution (QKD) from terrestrial limits of ˜200 km to global scales. We have developed a thorough numerical simulation using realistic simulated orbits and incorporating the effects of pointing error, diffraction, atmosphere and telescope design, to obtain estimates of the loss and background noise which a satellite-based system would experience. Combining with quantum optics simulations of sources and detection, we determine the length of secure key for QKD, as well as entanglement visibility and achievable distances for fundamental experiments. We analyse the performance of a low Earth orbit satellite for downlink and uplink scenarios of the quantum optical signals. We argue that the advantages of locating the quantum source on the ground justify a greater scientific interest in an uplink as compared to a downlink. An uplink with a ground transmitter of at least 25 cm diameter and a 30 cm receiver telescope on the satellite could be used to successfully perform QKD multiple times per week with either an entangled photon source or with a weak coherent pulse source, as well as perform long-distance Bell tests and quantum teleportation. Our model helps to resolve important design considerations such as operating wavelength, type and specifications of sources and detectors, telescope designs, specific orbits and ground station locations, in view of anticipated overall system performance.

Bourgoin, J.-P.; Meyer-Scott, E.; Higgins, B. L.; Helou, B.; Erven, C.; Hübel, H.; Kumar, B.; Hudson, D.; D'Souza, I.; Girard, R.; Laflamme, R.; Jennewein, T.

2013-02-01

106

Terrestrial Planet Atmospheres and Biosignatures  

NASA Astrophysics Data System (ADS)

The search for terrestrial exoplanets - rocky worlds in orbit around stars other than the Sun - is one of humanity's most exciting science goals. The discovery of super Earths, terrestrial planets more massive than Earth, has opened a new era in exoplanet science, confirming the basic idea that our solar system is not the only planetary system to harbor terrestrial planets. Terrestrial exoplanets will expand planetary diversity, with masses and compositions likely very different from those found in our solar system. Most significantly, terrestrial exoplanets have the potential to host habitable environments on or below their solid surfaces, and are the most likely places beyond our solar system to search for signs of life. In the coming decades, instrumentation will be developed to expand our census of terrestrial exoplanets and directly characterize the atmospheres and biosignatures of these worlds. In the meantime, scientific progress in this field is made via extensive photochemical, climate, and radiative transfer modeling of terrestrial planetary environments together with remote sensing studies of solar system terrestrial planets, including Earth. This chapter provides an overview of terrestrial exoplanet atmosphere modeling techniques, a review of the scientific advances to date, and a discussion of outstanding questions and future directions.

Meadows, V.; Seager, S.

107

Technical comparison of several global mobile satellite communications systems  

NASA Astrophysics Data System (ADS)

The era of satellite-based mobile satellite communications (MSC) systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept the space-based MSC systems from appealing to the wider market of personal mobile communications. The progress made over the last ten years, however, in digital voice processing, satellite technology, and component miniaturization has resulted in the viability of satellite-based mobile satellite communications systems to meet the growing market in personal mobile communications using handsets similar to those currently in use with land-based cellular systems. Three of the more mature LEO/MEO satellite systems are addressed in this paper including GLOBALSTAR, Iridium, and Odyssey. The system architectures of each system are presented along with a description of the satellite and user handset designs and the multiaccess techniques employed. It will be shown that, although a number of similarities exist among the system addressed, each system is unique in a variety of significant design areas. It is concluded that the technical feasibility of satellite-based mobile satellite communications systems seems to be secure. It will be challenging, however, for the vendors to actually develop and deploy these systems in a cost effective, timely, and reliable way that meets a continually evolving set of requirements based upon a rapidly changing technology base.

Comparetto, Gary M.

108

Evaluation of a moderate resolution, satellite-based impervious surface map using an independent, high-resolution validation data set  

USGS Publications Warehouse

Given the relatively high cost of mapping impervious surfaces at regional scales, substantial effort is being expended in the development of moderate-resolution, satellite-based methods for estimating impervious surface area (ISA). To rigorously assess the accuracy of these data products high quality, independently derived validation data are needed. High-resolution data were collected across a gradient of development within the Mid-Atlantic region to assess the accuracy of National Land Cover Data (NLCD) Landsat-based ISA estimates. Absolute error (satellite predicted area - "reference area") and relative error [satellite (predicted area - "reference area")/ "reference area"] were calculated for each of 240 sample regions that are each more than 15 Landsat pixels on a side. The ability to compile and examine ancillary data in a geographic information system environment provided for evaluation of both validation and NLCD data and afforded efficient exploration of observed errors. In a minority of cases, errors could be explained by temporal discontinuities between the date of satellite image capture and validation source data in rapidly changing places. In others, errors were created by vegetation cover over impervious surfaces and by other factors that bias the satellite processing algorithms. On average in the Mid-Atlantic region, the NLCD product underestimates ISA by approximately 5%. While the error range varies between 2 and 8%, this underestimation occurs regardless of development intensity. Through such analyses the errors, strengths, and weaknesses of particular satellite products can be explored to suggest appropriate uses for regional, satellite-based data in rapidly developing areas of environmental significance. ?? 2009 ASCE.

Jones, J. W.; Jarnagin, T.

2009-01-01

109

Terrestrial Planet Geophysics  

NASA Astrophysics Data System (ADS)

Terrestrial planet geophysics beyond our home sphere had its start arguably in the early 1960s, with Keith Runcorn contending that the second-degree shape of the Moon is due to convection and Mariner 2 flying past Venus and detecting no planetary magnetic field. Within a decade, in situ surface geophysical measurements were carried out on the Moon with the Apollo program, portions of the lunar magnetic and gravity fields were mapped, and Jack Lorell and his colleagues at JPL were producing spherical harmonic gravity field models for Mars using tracking data from Mariner 9, the first spacecraft to orbit another planet. Moreover, Mariner 10 discovered a planetary magnetic field at Mercury, and a young Sean Solomon was using geological evidence of surface contraction to constrain the thermal evolution of the innermost planet. In situ geophysical experiments (such as seismic networks) were essentially never carried out after Apollo, although they were sometimes planned just beyond the believability horizon in planetary mission queues. Over the last three decades, the discipline of terrestrial planet geophysics has matured, making the most out of orbital magnetic and gravity field data, altimetric measurements of surface topography, and the integration of geochemical information. Powerful constraints are provided by tectonic and volcanic information gleaned from surface images, and the engagement of geologists in geophysical exercises is actually quite useful. Accompanying these endeavors, modeling techniques, largely adopted from the Earth Science community, have become increasingly sophisticated and have been greatly enhanced by the dramatic increase in computing power over the last two decades. The future looks bright with exciting new data sets emerging from the MESSENGER mission to Mercury, the promise of the GRAIL gravity mission to the Moon, and the re-emergence of Venus as a worthy target for exploration. Who knows? With the unflagging optimism and persistence of a few diehards, we may eventually have a seismic and heat flow network on Mars.

Phillips, R. J.

2008-12-01

110

Terrestrial Planets Accreted Dry  

NASA Astrophysics Data System (ADS)

Plate tectonics shaped the Earth, whereas the Moon is a dry and inactive desert. Mars probably came to rest within the first billion years of its history, and Venus, although internally very active, has a dry inferno for its surface. The strong gravity field of a large planet allows for an enormous amount of gravitational energy to be released, causing the outer part of the planetary body to melt (magma ocean), helps retain water on the planet, and increases the pressure gradient. The weak gravity field and anhydrous conditions prevailing on the Moon stabilized, on top of its magma ocean, a thick buoyant plagioclase lithosphere, which insulated the molten interior. On Earth, the buoyant hydrous phases (serpentines) produced by reactions between the terrestrial magma ocean and the wet impactors received from the outer Solar System isolated the magma and kept it molten for some few tens of million years. The elemental distributions and the range of condensation temperatures show that the planets from the inner Solar System accreted dry. The interior of planets that lost up to 95% of their K cannot contain much water. Foundering of their wet surface material softened the terrestrial mantle and set the scene for the onset of plate tectonics. This very same process may have removed all the water from the surface of Venus 500 My ago and added enough water to its mantle to make its internal dynamics very strong and keep the surface very young. Because of a radius smaller than that of the Earth, not enough water could be drawn into the Martian mantle before it was lost to space and Martian plate tectonics never began. The radius of a planet therefore is the key parameter controlling most of its evolutional features.

Albarede, F.; Blichert-Toft, J.

2007-12-01

111

Iridium: Covering the globe with personal communication  

NASA Astrophysics Data System (ADS)

It has become abundantly clear that available, reliable telecommunications is a critical requirement for effective economic development, and that most of the worlds population lacks effective telecommunications today, even on a local basis, with international capability being particularly deficient. The IRIDIUM system, a satellite based communications system utilizing Low Earth Orbit (LEO) satellites, will bring personal communications to every part of the world. This networked LEO system will provide an efficient means of interconnecting hundreds of thousands of towns and villages more cost effectively than any other known approach. Various aspects of the system are discussed.

Gercenstein, Mark

112

Primitive Terrestrial Atmospheres  

NASA Astrophysics Data System (ADS)

A 23.3 year periodicity preserved in a 2500 million year old banded iron-formation is interpreted as reflecting the climatic influence of the lunar nodal tide, the signature of which has been detected in the modern climate. The lunar distance is deduced to have been 52 Earth radii. The influence of the lunar nodal tide is also detected in varves dating to 680 million years B.P. The implied history of Precambrian tidal friction is in excellent agreement with both more recent paleontological evidence and the long -term stability of the lunar orbit. The solar semidiurnal thermal tide was resonant with the natural period of the atmosphere when the day was (TURN)21.3 hours. This took place at the end of the Precambrian. The resonant atmospheric tide would have been large enough (.01 bar at the surface) to have influenced the weather. In contrast to lunar oceanic tides, the gravitational torque on the thermal tide accelerates the Earth's rotation rate; near resonance the opposing torques were comparable, so that the day may have been stabilized near 21.3 hours for much of the Precambrian. A sustained resonance does not conflict with the available evidence. Methane photochemistry in the primitive terrestrial atmosphere is studied using a detailed numerical model. Methane is oxidized cleanly and efficiently provided CO(,2) is more abundant than CH(,4). If CH(,4) and CO(,2) abundances are comparable, a large fraction of the methane present is polymerized, forming alkanes in the troposphere and polyacetylenes and nitriles in the upper atmosphere. Production of HCN from CH(,4) and N(,2) in the anaerobic atmosphere and its subsequent removal in rainwater could have been efficient; net production varying from .01% to 10% of the methane consumed. In the absence of a magnetic field, high ancient solar EUV and X-ray fluxes would have permitted an ocean of hydrogen to escape as a transsonic wind from a primordial accretionary greenhouse atmosphere in as little as 25 million years. The terrestrial magnetic field would have been strong enough to have prevented a freely flowing wind, reducing escape by one or two orders of magnitude with respect to an otherwise identical Venus.

Zahnle, Kevin John

1985-12-01

113

Terrestrial locomotion in arachnids.  

PubMed

In this review, we assess the current state of knowledge on terrestrial locomotion in Arachnida. Arachnids represent a single diverse (>100,000 species) clade containing well-defined subgroups (at both the order and subordinal levels) that vary morphologically around a basic body plan, yet exhibit highly disparate limb usage, running performance, and tarsal attachment mechanisms. Spiders (Araneae), scorpions (Scorpiones), and harvestmen (Opiliones) have received the most attention in the literature, while some orders have never been subject to rigorous mechanical characterization. Most well-characterized taxa move with gaits analogous to the alternating tripod gaits that characterize fast-moving Insecta - alternating tetrapods or alternating tripods (when one pair of legs is lifted from the ground for some other function). However, between taxa, there is considerable variation in the regularity of phasing between legs. Both large and small spiders appear to show a large amount of variation in the distribution of foot-ground contact, even between consecutive step-cycles of a single run. Mechanisms for attachment to vertical surfaces also vary, and may depend on tufts of adhesive hairs, fluid adhesives, silks, or a combination of these. We conclude that Arachnida, particularly with improvements in microelectronic force sensing technology, can serve as a powerful study system for understanding the kinematics, dynamics, and ecological correlates of sprawled-posture locomotion. PMID:22326455

Spagna, Joseph C; Peattie, Anne M

2012-02-08

114

Utility terrestrial biodiversity issues  

NASA Astrophysics Data System (ADS)

Results from a survey of power utility biologists indicate that terrestrial biodiversity is considered a major issue by only a few utilities; however, a majority believe it may be a future issue. Over half of the respondents indicated that their company is involved in some management for biodiversity, and nearly all feel that it should be a goal for resource management. Only a few utilities are funding biodiversity research, but a majority felt more research was needed. Generally, larger utilities with extensive land holdings had greater opportunities and resources for biodiversity management. Biodiversity will most likely be a concern with transmission rights-of-way construction and maintenance, endangered species issues and general land resource management, including mining reclamation and hydro relicensing commitments. Over half of the companies surveyed have established voluntary partnerships with management groups, and biodiversity is a goal in nearly all the joint projects. Endangered species management and protection, prevention of forest fragmentation, wetland protection, and habitat creation and protection are the most common partnerships involving utility companies. Common management practices and unique approaches are presented, along with details of the survey.

Breece, Gary Allen; Ward, Bobby J.

1996-11-01

115

Utility terrestrial biodiversity issues  

SciTech Connect

Results from a survey of power utility biologists indicate that terrestrial biodiversity is considered a major issued by only a few utilities; however, a majority believe it may be a future issue. Over half of the respondents indicated that their company is involved in some management for biodiversity, and nearly all feel that it should be a goal for resource management. Only a few utilities are funding biodiversity research, but a majority felt more research was needed. Generally, larger utilities with extensive land holdings had greater opportunities and resources for biodiversity management. Biodiversity will most likely be a concern with transmission rights-of-way construction and maintenance, endangered species issues and general land resource management, including mining reclamation and hydro relicensing commitments. Over half of the companies surveyed have established voluntary partnerships with management groups, and biodiversity is a goal in nearly all the joint projects. Endangered species management and protection, prevention of forest fragmentation, wetland protection, and habitat creation and protection are the most common partnerships involving utility companies. Common management practices and unique approaches are presented, along with details of the survey. 4 refs.

Breece, G.A. [Southern Company, Atlanta, GA (United States); Ward, B.J. [Carolina Power and Light Company, Raleigh, NC (United States)

1996-11-01

116

GEOLogic: Terrestrial and Jovian Planets  

NSDL National Science Digital Library

In this two-part example, students are given clues about properties about the terrestrial and Jovian planets respectively and asked to match up the planet with the correct equatorial radius, mean orbital velocity, and period of rotation.

Guertin, Laura

117

Contaminant Exposure in Terrestrial Vertebrates  

EPA Science Inventory

Manuscript is a critical review of the state of the science for quantifying exposures of terrestrial wildlife species to chemical contamination. It describes the unique aspects of birds, mammals, reptiles, amphibians and threatened and endangered species. Fate and transport of ...

118

USING TERRESTRIAL PLANTS IN BIOMONITORING  

EPA Science Inventory

Terrestrial plants have been used as monitors of environmental pollutants since at least the beginning of this century & have recently received attention in response to the need for ecological assessments at hazardous waste sites & monitoring pesticide damage to nontarget plants....

119

Commercial aerospace and terrestrial applications of nickel-hydrogen batteries  

Microsoft Academic Search

The nickel-hydrogen battery system, used extensively in the aerospace industry to supply electrical power to earth-orbital satellites for communications, observation, and military applications, is being developed for commercial, terrestrial applications. Low-cost components, electrodes, cell designs, and battery designs are currently being tested. Catalytic hydrogen electrodes have been developed which are compatible with commercial nickel battery cost. Prismatic and spiral-wound cell

Dwight B. Caldwell; Dwaine K. Coates; Chris L. Fox; Lee E. Miller

1996-01-01

120

Application of Satellite Based Imagery and Altimetry to Estimation of River Hydraulics and Remote Estimation of River Discharge  

NASA Astrophysics Data System (ADS)

The response, or residual, of hydrologic climate variables on the land surface is river discharge. The flow in a river reflects the difference between precipitation on the land surface and evapotranspiration from the land surface, and incorporates the surface and groundwater runoff components of the combined effect of land cover, soil characteristics, soil moisture, and subsurface flow from aquifers. As such, river discharge is a fundamental hydrologic variable that needs to be quantified in order to assess any element of the land surface hydrology. Typically, river discharge is measured on the ground at specific locations in a river. A stream gage requires not only tracking of hydraulic variables at many locations but many direct measurements of discharge at each location through any given year to track change and derive relationships between the measured hydraulic variables. These direct measurements require manpower and are limited by cost and accessibility. Remote sensing offers wide spatial coverage and the possibility measuring hydraulic variables that can enable discharge to be deduced. This would serve as a useful tool supplementing on-the-ground stream gaging networks and providing data for regions where data or location are inaccessible. We explore here the application of remotely sensed river width and river water-surface height (stage and slope) to estimate the discharge, depth, and velocity of rivers. The imagery is based on Landsat ETM+ and TM Imagery acquired between 2002 and 2009. With a combination of manual digitization and automatic classification methods, the river section area at four designated river reaches on the Mississippi/Missouri river basin were determined. Accuracy assessments were made in terms of method and the effects of clouds, snow, and ice. A time series of water-surface areas for each location were thus developed, and found to show seasonal variability correlated with seasonal discharge. However, a reasonable correlation between river surface area and discharge was not found at all of the sites, indicating that width-discharge relations will not always provide consistent and reasonable estimates of the river discharge. The ICESat/GLAS laser altimeter and the NASA/CNES OSTM and ESA ENVISAT radar altimeters also cross these river reaches at specific locations. Deduced altimetric surface elevation variations based on GLA14/GLA06 and GDR data sets for the 2002-2010 period show variable accuracy when compared to gauge data, but are used to derive surface slope estimates. The combined satellite-based parameters provide reasonable estimates of river discharge, depth, and velocity. Issues concerning the satellite-based observation frequency, and the accuracy of the altimetric and imaging estimates are evaluated and discussed with regard to the resolution and monitoring of river hydraulic conditions.

Bjerklie, D. M.; Birkett, C. M.; Li, Y.; Dubayah, R.; Hofton, M. A.

2010-12-01

121

Carbon Sequestration in Terrestrial Ecosystems  

Microsoft Academic Search

CSiTE, the Department of Energy's research consortium performs fundamental research in support of new methods to enhance carbon sequestration in terrestrial ecosystems in an environmentally acceptable manner. The goal of CSiTE is to discover and characterize links between critical pathways and mechanisms across scales from the molecular to the landscape for creating larger, longer-lasting carbon pools in terrestrial ecosystems. This

G. K. Jacobs; W. M. Post; J. D. Jastrow; R. C. Izaurralde

2002-01-01

122

Assessing satellite-based rainfall estimates in semi-arid watersheds using the USDA-ARS Walnut Gulch gauge network and TRMM-PR  

Technology Transfer Automated Retrieval System (TEKTRAN)

The rain gauge network associated with the U.S. Department of Agriculture, Agricultural Research Service Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona provides a unique opportunity for direct comparisons of in-situ measurements and satellite-based instantaneous rain-rate estimat...

123

Land mobile communications satellite missions in Europe  

NASA Astrophysics Data System (ADS)

A market survey of the potential needs for land mobile communications in Europe in 1995 and 2005 was carried out. There is an exploding demand for land mobile communications in Europe. This demand justifies that every effort be made to develop as fast as possible a compatible pan-European terrestrial mobile system. The potential remaining needs, outside of the presently planned terrestrial mobile system, which can be served only by satellite, could exceed the capacity of a single medium size communications satellite in the available state of the art technology.

Deverdiere, R.

1986-09-01

124

Comparison of ocean surface solar irradiance in the GLA General Circulation Model and satellite-based calculations  

SciTech Connect

A global, 7-year satellite-based record of ocean surface solar irradiance (SSI) is used to assess the realism of ocean SSI simulated by the nine-layer Goddard Laboratory for Atmospheres (GLA) General Circulation Model (GCM). January and July climatologies of net SSI produced by the model are compared with corresponding satellite climatologies for the world oceans between 54[degrees]N and 54[degrees]S. This comparison of climatologies indicates areas of strengths and weaknesses in the GCM treatment of cloud-radiation interactions, the major source of model uncertainty. Realism of ocean SSI is also important for applications such as incorporating the GLA GCM into a coupled ocean-atmosphere GCM. The results show that the GLA GCM simulates too much SSI in the extratropics and too little in the tropics, especially in the summer hemisphere. These discrepancies reach magnitudes of 60 W m[sup [minus]2] and more. The discrepancies are particularly large in the July case off the western coast of North America. In this region of persistent marine stratus, the GCM climatological values exceed the satellite climatological values by as much as 131 W m[sup [minus]2]. Positive and negative discrepancies in SSI are shown to be consistent with discrepancies in planetary albedo.

Chertock, B. (NOAA/Environmental Research Laboratories, Boulder, CO (United States)); Sud, Y.C. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States))

1993-03-01

125

Assessing the performance of satellite-based precipitation products and its dependence on topography over Poyang Lake basin  

NASA Astrophysics Data System (ADS)

Satellite-based precipitation products (SPPs) have greatly improved their applicability and are expected to offer an alternative to ground-based precipitation estimates in the present and the foreseeable future. There is a strong need for a quantitative evaluation of the usefulness and limitations of SPPs in operational meteorology and hydrology. This study compared two widely used high-resolution SPPs, the Tropical Rainfall Measuring Mission (TRMM) and Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN) in Poyang Lake basin which is located in the middle reach of the Yangtze River in China. The bias of rainfall amount and occurrence frequency under different rainfall intensities and the dependence of SPPs performance on elevation and slope were investigated using different statistical indices. The results revealed that (1) TRMM 3B42 usually underestimates the rainy days and overestimates the average rainfall as well as annual rainfall, while the PERSIANN data were markedly lower than rain gauge data; (2) the rainfall contribution rates were underestimated by TRMM 3B42 in the middle rainfall class but overestimated in the heavy rainfall class, while the opposite trend was observed for PERSIANN; (3) although the temporal distribution characteristics of monthly rainfall were correctly described by both SPPs, PERSIANN tended to suffer a systematic underestimation of rainfall in every month; and (4) the performances of both SPPs had clear dependence on elevation and slope, and their relationships can be fitted using quadratic equations.

Li, Xianghu; Zhang, Qi; Xu, Chong-Yu

2013-05-01

126

Ground-truthing a satellite-based night-time cloud identification technique at the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

Atmospheric conditions are important factors for the cosmic rays detected at the Pierre Auger Observatory. Therefore, we have been accumulating different type of atmospheric data during the last 8 years. This can also be a very interesting source for research for atmospheric scientists. As an illustration of interdisciplinary science, we have used satellite data to identify clouds at night. We developed a method using infrared data from the imager instrument on the GOES-12 satellite. The Pierre Auger Observatory has already installed ground-based instruments, like the Central Laser Facility (CLF), for identifying clouds at night. The Fluorescence Detector (FD) of the Pierre Auger Observatory sees the CLF laser profile and thereby senses the presence of clouds directly above the CLF. For the satellite image pixel encompassing the CLF, we compared cloud identifications with the satellite-based method to those made with the FD observations of CLF laser events. The results of both methods agree. We generate cloud probability maps covering the region of the observatory for all periods of FD operation since 2007. We summarize the cloud cover history of the observatory site as well.

Chirinos, J.

2012-08-01

127

A satellite-based method for monitoring seasonality in the overstory leaf area index of Siberian larch forest  

NASA Astrophysics Data System (ADS)

Reliable monitoring of the leaf area index (LAI) is required to further understand the carbon, water, and energy cycles of forests. In this study, we proposed a new satellite-based method to estimate the overstory LAI (LAIo) separately from the understory LAI (LAIu) for larch forests covering eastern Siberia. We modeled forest scenes representative of larch forest structure, with particular consideration of the typical clumped shoot structure of larch. Three-dimensional radiative transfer simulations were then conducted under various forest conditions to establish the relationships between LAIo and seasonal increases in the normalized difference water index after leaf appearance. Model-based sensitivity analyses indicated a maximum error of up to 26% under known noise levels. Averaged at the continental scale, total LAI from our estimates, the CYCLOPES version 3.1, and the Moderate Resolution Imaging Spectroradiometer MOD15 Collection 5 (main algorithm) showed similar ranges in summer. However, spatial pattern of LAI was slightly different, with smoother variability for CYCLOPES LAI. Our LAI and CYLOPES effective LAI reproduced a realistic seasonal variation with exact timing of spring increase in LAIo. The main drawbacks of MOD15 Collection 5 were unrealistically strong temporal variability, and the fact that LAI began to increase earlier than the overstory leaf appearance date. Overall, the results show that our new method is a good alternative to MOD15 Collection 5 and CYCLOPES, as it provides separate estimates of LAIo and LAIu and true LAI instead of effective LAI.

Kobayashi, Hideki; Delbart, Nicolas; Suzuki, Rikie; Kushida, Keiji

2010-03-01

128

Satellite-based assessment of cloud-free net radiative effect of dust aerosols over the Atlantic Ocean  

NASA Astrophysics Data System (ADS)

Using eighteen months (June-August, 2000-2005) of spatially and temporally collocated Moderate Resolution Imaging Spectroradiometer (MODIS) and the Clouds and the Earth's Radiant Energy System (CERES) data from the Terra satellite over the Atlantic Ocean [10W-60W, 0-30N], we first separate the dust aerosol optical thickness at 0.55 ?m (AOT) from the total column MODIS AOT. We then calculate the cloud-free TOA net radiative effect (NRE) of dust aerosols by accounting for diurnal effects and sample biases. The cloud-free NRE is -6.31 ± 1.16 Wm-2 and nearly twenty percent of the shortwave radiative effect (-7.75 ± 0.86 Wm-2) is cancelled by the longwave radiative effect (+1.44 ± 0.57 Wm-2) indicating the importance of the dust aerosols in the thermal portion of the electromagnetic spectrum. This is the first multi-year satellite-based assessment of the NRE of dust aerosols indicating the importance of both the shortwave and longwave radiative effects of dust aerosols over the oceans unlike anthropogenic aerosols that have negligible TOA longwave radiative forcing effects.

Christopher, Sundar A.; Jones, Thomas

2007-01-01

129

Wireless communication employing high altitude long endurance aeronautical platforms  

Microsoft Academic Search

This article presents a possible alternative solution for wireless service providers. Wireless communication is currently the fastest developing branch in telecommunications. The number of wireless, especially mobile, subscribers is increasing at a much faster rate than the number of wire subscribers. Today, wireless communication is divided into terrestrial and satellite communications, both of which bring with it certain benefits and

S. Tomazic; A. Vugrinec; P. Skraba

2000-01-01

130

AQA-PM: Extension of the Air-Quality model for Austria with satellite based Particulate Matter estimates  

NASA Astrophysics Data System (ADS)

Air quality is a key element for the well-being and quality of life of European citizens. Air pollution measurements and modeling tools are essential for assessment of air quality according to EU legislation. The responsibilities of ZAMG as the national weather service of Austria include the support of the federal states and the public in questions connected to the protection of the environment in the frame of advisory and counseling services as well as expert opinions. The Air Quality model for Austria (AQA) is operated at ZAMG in cooperation with the University of Natural Resources and Applied Life Sciences in Vienna (BOKU) by order of the regional governments since 2005. AQA conducts daily forecasts of gaseous and particulate (PM10) air pollutants over Austria. In the frame of the project AQA-PM (funded by FFG), satellite measurements of the Aerosol Optical Thickness (AOT) and ground-based PM10-measurements are combined to highly-resolved initial fields using assimilation techniques. It is expected that the assimilation of satellite measurements will significantly improve the quality of AQA. Currently no observations are considered in the modeling system. At the current stage of the project, different datasets have been collected (ground measurements, satellite measurements, fine resolved regional emission inventories) and are analyzed and prepared for further processing. This contribution gives an overview of the project working plan and the upcoming developments. The goal of this project is to improve the PM10-forecasts for Austria with the integration of satellite based measurements and to provide a comprehensive product-platform.

Hirtl, M.; Mantovani, S.; Krüger, B. C.; Triebnig, G.

2012-04-01

131

A Satellite-Based Method for Estimating Global Oceanic DMS and Its Application in a 3-D Atmospheric GCM  

SciTech Connect

The flux of dimethylsulfide (DMS) from the world's oceans is the largest known source of biogenically-derived reduced sulfur compounds to the atmosphere. Its impact on atmospheric chemistry and radiative transfer is an active area of scientific research, and DMS is routinely included in three-dimensional global climate change and chemical transport models. In such models, DMS fluxes typically are based on global sea surface DMS concentrations and wind-speed-dependent parameterizations of the mass transfer coefficient. We show here how sea surface DMS concentrations can be estimated from satellite-based Sea-viewing Wide Field-of-View Sensor (SeaWiFS) observations of sea surface chlorophyll a. We compare SeaWiFS-derived DMS concentrations for the twelve month period November 1997 through October 1998 with shipboard measurements made in the Pacific and Indian Oceans. The SeaWiFS-derived DMS distributions demonstrate improved capture of DMS spatial variability in Southern Ocean surface waters relative to previous works, but underestimate the amplitude of seasonal DMS variations in this region. Using the three-dimensional Atmospheric General Circulation Model of the Laboratoire de M?orologie Dynamique, model-time-step wind speeds, an atmospheric-stability-dependent parameterization of the mass transfer coefficient, and our SeaWiFS-derived oceanic DMS distributions, we estimate an annual Southern Ocean DMS emission of 6.8 Tg S yr-1. This value represents approximately one-third of the annual global DMS marine emission, and underscores the importance of this region as a source of natural sulfur emissions.

Belviso, S.; Moulin, C.; Bopp, L.; Cosme, E.; Chapman, Elaine G.; Aranami, K.

2003-01-01

132

AQA-PM: Extension of the Air-Quality Model For Austria with Satellite based Particulate Matter Estimates  

NASA Astrophysics Data System (ADS)

Air quality is a key element for the well-being and quality of life of European citizens. Air pollution measurements and modeling tools are essential for assessment of air quality according to EU legislation. The responsibilities of ZAMG as the national weather service of Austria include the support of the federal states and the public in questions connected to the protection of the environment in the frame of advisory and counseling services as well as expert opinions. The Air Quality model for Austria (AQA) is operated at ZAMG in cooperation with the University of Natural Resources and Life Sciences in Vienna (BOKU) by order of the regional governments since 2005. AQA conducts daily forecasts of gaseous and particulate (PM10) air pollutants over Austria. In the frame of the project AQA-PM (funded by FFG), satellite measurements of the Aerosol Optical Thickness (AOT) and ground-based PM10-measurements are combined to highly-resolved initial fields using regression- and assimilation techniques. For the model simulations WRF/Chem is used with a resolution of 3 km over the alpine region. Interfaces have been developed to account for the different measurements as input data. The available local emission inventories provided by the different Austrian regional governments were harmonized and used for the model simulations. An episode in February 2010 is chosen for the model evaluation. During that month exceedances of PM10-thresholds occurred at many measurement stations of the Austrian network. Different model runs (only model/only ground stations assimilated/satellite and ground stations assimilated) are compared to the respective measurements. The goal of this project is to improve the PM10-forecasts for Austria with the integration of satellite based measurements and to provide a comprehensive product-platform.

Hirtl, Marcus; Mantovani, Simone; Krüger, Bernd C.; Triebnig, Gerhard; Flandorfer, Claudia

2013-04-01

133

Hourly soil moisture mapping over West Africa using AMSR-E observations and a satellite-based rainfall product  

NASA Astrophysics Data System (ADS)

This paper provides an original and simple methodology to map surface soil moisture with a fine temporal and spatial resolution over large areas based on a satellite rainfall accumulation product and soil microwave emission measurements at C-band. The first motivation of this study was to obtain high temporal frequency (~1 h) in order to study the possible feedback mechanisms between soil moisture and convection in West Africa. The use of soil moisture maps derived from satellite microwave measurements was not possible due to the low (at best daily) temporal resolution. Thus, a rainfall accumulation product based on Meteosat geostationary satellite measurements was used together with a simple Antecedent Precipitation Index (API) model to produce soil moisture map at the 10×10 km2 and 30 min resolution. Due to uncertainties on the satellite-based rainfall accumulation product, derived soil moisture maps were found to be erroneous. An assimilation technique based on AMSR-E C-band measurements into a microwave emission model was developed. The assimilation technique described in this study consists of modulating the rainfall accumulation estimate between two successive AMSR-E brightness temperatures (TB) measurements in order to match simulated and observed TB. When a rainfall event happens, the initial rainfall accumulation estimate is modulated using a multiplicative factor ranging from 0 to 7. The best solution is given by the rainfall rate which minimizes the difference between observed and simulated TB. Ground-based soil moisture measurements obtained at three sites in Niger, Mali and Benin were used to assess the methodology which was found to improve the soil moisture estimates over the three sites.

Pellarin, T.; Tran, T.; Cohard, J.-M.; Galle, S.; Laurent, J.-P.; de Rosnay, P.; Vischel, T.

2009-06-01

134

Terrestrial ecosystems and climatic change  

SciTech Connect

The structure and function of terrestrial ecosystems depend on climate, and in turn, ecosystems influence atmospheric composition and climate. A comprehensive, global model of terrestrial ecosystem dynamics is needed. A hierarchical approach appears advisable given currently available concepts, data, and formalisms. The organization of models can be based on the temporal scales involved. A rapidly responding model describes the processes associated with photosynthesis, including carbon, moisture, and heat exchange with the atmosphere. An intermediate model handles subannual variations that are closely associated with allocation and seasonal changes in productivity and decomposition. A slow response model describes plant growth and succession with associated element cycling over decades and centuries. These three levels of terrestrial models are linked through common specifications of environmental conditions and constrain each other. 58 refs.

Emanuel, W.R. (Oak Ridge National Lab., TN (USA)); Schimel, D.S. (Colorado State Univ., Fort Collins, CO (USA). Natural Resources Ecology Lab.)

1990-01-01

135

Space Physics and Terrestrial Effects  

NSDL National Science Digital Library

This curriculum guide is intended for high school teachers who are teaching solar physics, especially the effects of solar activity on terrestrial planets. The chapters discuss stellar evolution, the structure of the sun, studying the sun, and solar and terrestrial interactions. Lab activities provided include: building a spectroscope, energy transport within the sun, measuring the solar constant, luminosity of the sun and stars, seeing different wavelengths, the Earth-Sun orientation, the effect of the solar wind on the geomagnetic field, determining the rotation period of the sun, and radiation hazards in space.

2005-05-23

136

Proactive TCP Mechanism to Improve Handover Performance in Mobile Satellite and Terrestrial Networks  

NASA Astrophysics Data System (ADS)

Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper protocol layers and TCP (Transmission Control Protocol) is one of them. This space segment technology as well as terrestrial technology, is characterized by periodic variations in communication properties and coverage causing the termination of ongoing call as connections of Mobile Nodes (MN) alter stochastically. Although provisions are made to provide efficient communication infrastructure this hybrid space and terrestrial networks must ensure the end-to-end network performance so that MN can move seamlessly among these networks. However from connectivity point of view current TCP performance has not been engineered for mobility events in multi-radio MN. Traditionally, TCP has applied a set of congestion control algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery) to probe the currently available bandwidth on the connection path. These algorithms need several round-trip times to find the correct transmission rate (i.e. congestion window), and adapt to sudden changes connectivity due to handover. While there are protocols to maintain the connection continuity on mobility events, such as Mobile IP (MIP) and Host Identity Protocol (HIP), TCP performance engineering has had less attention. TCP is implemented as a separate component in an operating system, and is therefore often unaware of the mobility events or the nature of multi-radios' communication. This paper aims to improve TCP communication performance in Mobile satellite and terrestrial networks.

Vinayakray-Jani, Preetida; Sanyal, Sugata

2012-06-01

137

Trends in Oceanic Evaporation retrieved from the Goddard Satellite-based Surface Turbulent Fluxes based on SSM\\/I v6 (GSSTF2b) Dataset  

Microsoft Academic Search

Trends and variability in global oceanic evaporation data sets have been examined for the period 1988-2000 by Chiu et al. (Acta Oceanologica Sinica, 2008). These data sets are satellite estimates based on bulk aerodynamic formulations and include the NASA\\/Goddard Space Flight Center Satellite-based Surface Turbulent Flux version 2 (GSSTF2), the Japanese-Ocean Flux Using Remote Sensing Observations (J-OFURO), the Hamburg Ocean-Atmosphere

S. Gao; R. Chokngamwong; L. Chiu; C. Shie; P. P. Xie; R. F. Adler; E. J. Nelkin

2009-01-01

138

Terrestrial Energy Storage SPS Systems.  

National Technical Information Service (NTIS)

Terrestrial energy storage systems for the SSP system were evaluated that could maintain the 1.2 GW power level during periods of brief outages from the solar powered satellite (SPS). Short-term outages of ten minutes and long-term outages up to four hour...

H. W. Brandhorst

1998-01-01

139

Ionospheres of the terrestrial planets  

Microsoft Academic Search

The theory and observations relating to the ionospheres of the terrestrial planets Venus, the earth and Mars are reviewed. Emphasis is placed on comparing the basic differences and similarities between the planetary ionospheres. The review covers the plasma and electric-magnetic field environments that surround the planets, the theory leading to the creation and transport of ionization in the ionspheres, the

R. W. Schunk; A. F. Nagy

1980-01-01

140

The neoichnology of terrestrial arthropods  

Microsoft Academic Search

A comprehensive systematic neoichnological study was conducted to investigate the affect of substrate conditions on the morphology and survivorship of terrestrial arthropod trackways. Experiments utilized five different extant arthropods, representing a range of body forms and higher taxa: discoid cockroaches (Blaberus discoidalis), emperor scorpions (Pandinus imperator), Chilean rose tarantulas (Grammostola rosea), African giant black millipedes (Archispirostreptus gigas), and common woodlice

Robert B. Davis; Nicholas J. Minter; Simon J. Braddy

2007-01-01

141

Beam wander experiments: terrestrial path  

Microsoft Academic Search

We report on a set of measurements made in December 2005 by researchers from the University of Central Florida, SPAWAR's Innovative Science and Technology Experiment Facility (ISTEF), Harris Corporation, NASA Kennedy Space Center, and Northrop Grumman. The experiments were conducted on the Shuttle Landing Facility (SLF) at Kennedy Space Center (KSC) over terrestrial paths of 1, 2, and 5 km.

R. L. Phillips; L. C. Andrews; J. Stryjewski; B. Griffis; M. Borbath; D. Galus; G. Burdge; K. Green; C. Kim; D. Stack; C. Harkrider; D. Wayne; D. Hand; J. Kiriazes

2006-01-01

142

Evaluation of Satellite-based Real-time Global Flood Detection and Prediction System with an Improved Hydrological Model  

NASA Astrophysics Data System (ADS)

Floods are common and costly natural disasters. A real-time global flood monitoring system (GFMS) has been routinely running for several years with simplified hydrological algorithms driven by Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42RT rainfall (http://trmm.gsfc.nasa.gov). The main limitations of the current operational real-time GFMS include the errors from both precipitation estimates and hydrological model. To improve the real-time global flood detection and predicting, a new generation of GFMS is under development using improved satellite-based rainfall data and an improved hydrological model. The Coupled Routing and Excess Storage (CREST) hydrological model (reference Wang et al.), characterized as distributed runoff generation coupled with cell-to-cell routing, has been developed and implemented for the globe at 1/8 degree spatial resolution and 3-hourly time interval. The global hydrography data derived by Dominant River Tracing (DRT) algorithm was employed to provide the model with vital and accurate upscaled drainage network information, e.g. flow direction, flow distance, flow accumulation. In order to validate the modeling system, the CREST model was calibrated and validated over dozens of global basins, while this talk will mainly focus on a further validation of the modeling system by evaluating its ability in detecting recorded historic (1998-2010) flood events. Global retrospective hydrological simulations were conducted using the CREST model driven by 12-year TMPA 3B42V6 rainfall (including 1-year model spin-up). The simulated flood events were defined according to Log Pearson-III flood frequency curve based on the simulated retrospective stream flow. The performance of the model in detecting historical floods was quantified by the probability of detection and false alarm rate, calculated by comparing the simulated flood events with the recorded global flood databases (e.g. Dartmouth Flood Observatory (www.dartmouth.edu/~floods); Global Flood Inventory Database, Adhikaria et al., 2010). The improvements shown in the evaluations provide confidence in the new generation GFMS and point toward the Global Precipitation Measurement (GPM) era with improved multi-satellite precipitation observations.

Wu, H.; Adler, R. F.; Hong, Y.; Tian, Y.; Policelli, F.

2010-12-01

143

Use of satellite-based aerosol optical depth and spatial clustering to predict ambient PM2.5 concentrations  

PubMed Central

Satellite-based PM2.5 monitoring has the potential to complement ground PM2.5 monitoring networks, especially for regions with sparsely distributed monitors. Satellite remote sensing provides data on aerosol optical depth (AOD), which reflects particle abundance in the atmospheric column. Thus AOD has been used in statistical models to predict ground-level PM2.5 concentrations. However, previous studies have shown that AOD may not be a strong predictor of PM2.5 ground levels. Another shortcoming of remote sensing is the large number of non-retrieval days (i.e., days without satellite data available) due to clouds and snow- and ice-cover. In this paper we propose statistical approaches to overcome these two shortcomings, thereby making satellite imagery a viable method to estimate PM2.5 concentrations. First, we render AOD a robust predictor of PM2.5 mass concentration by introducing an AOD daily calibration approach through the use of mixed effects model. Second, we develop models that combine AOD and ground monitoring data to predict PM2.5 concentrations during non-retrieval days. A key feature of this approach is that we develop these prediction models separately for groups of days defined by the observed amount of spatial heterogeneity in concentrations across the study region. Subsequently, these methodologies were applied to examine the spatial and temporal patterns of daily PM2.5 concentrations for both retrieval days (i.e., days with satellite data available) and non-retrieval days in the New England region of the U.S. during the period 2000-2008. Overall, for the years 2000-2008, our statistical models predicted surface PM2.5 concentrations with reasonably high R2 (0.83) and low percent mean relative error (3.5%). Also the spatial distribution of the estimated PM2.5 levels in the study domain clearly exhibited densely populated and high traffic areas. The method we have developed demonstrates that remote sensing can have a tremendous impact on the fields of environmental monitoring and human exposure assessment.

Lee, Hyung Joo; Coull, Brent A.; Bell, Michelle L.; Koutrakis, Petros

2012-01-01

144

Analysis of the Eyjafjallajökull Eruption using the WRF-Chem Model compared to Satellite-Based Ash Retrieval Algorithms  

NASA Astrophysics Data System (ADS)

On April 14th, 2010, the long-dormant ice-capped volcano Eyjafjallajökull in southern Iceland exhibited a black ash-rich plume that quickly developed into an upper-tropospheric ash-cloud covering large parts of Europe grounding the majority of European air traffic for days. The emission of the ash-cloud continued for three days before the eruption turned more magmatic on April 18th. Due to a strong jet stream the plume initially drifted towards the United Kingdom and Norway with ash-fall occurring in many cities in both countries. Over the course of a week, most countries in Europe were affected by the dispersing cloud resulting in numbers of closed airports never seen before, grounded planes and confused passengers. This eruption, although small on the international scale, drew volcanic hazards into the public eye and called for better understanding of evolving volcanic plumes and their ash content. The Weather Research and Forecast model (WRF) coupled with Chemistry (Chem) has been utilized to use wind fields and chemical compositions to forecast the drift and chemical alteration of dispersed substances such as forest fires and volcanic ash and, in this study, was used to simulate the developing plume in time, based on physical input parameters of the initial plume as well as the wind patterns over Europe during April 2010. The results of this model have been compared to satellite-based ash retrieval algorithms like the Reverse Absorption Method and the Principal Component Analysis using Advanced Very High Resolution Radiometer (AVHRR) the Moderate-Resolution Imaging Spectroradiometer (MODIS) data. This comparison allows both, the ratification of the model as a forecasting tool and of the satellites as an in-situ measurement. Both parts are essential components to be able to predict and analyze airborne volcanic ash and to constantly improve the hazard assessment of ash cloud forecasting to minimize the burden on the aviation community while maximizing the protection thereof. This work supports the development of airborne ash concentration forecasts that is now being developed as an operational ash product.

Steensen, T. S.; Stuefer, M.; Webley, P.; Grell, G. A.; de Freitas, S. R.

2010-12-01

145

Satellite-based prediction of pCO2 in coastal waters of the eastern North Pacific  

NASA Astrophysics Data System (ADS)

Continental margin carbon cycling is complex, highly variable over a range of space and time scales, and forced by multiple physical and biogeochemical drivers. Predictions of globally significant air-sea CO2 fluxes in these regions have been extrapolated based on very sparse data sets. We present here a method for predicting coastal surface-water pCO2 from remote-sensing data, based on self organizing maps (SOMs) and a nonlinear semi-empirical model of surface water carbonate chemistry. The model used simple empirical relationships between carbonate chemistry (total dissolved carbon dioxide (T) and alkalinity (TAlk)) and satellite data (sea surface temperature (SST) and chlorophyll (Chl)). Surface-water CO2 partial pressure (pCO2) was calculated from the empirically-predicted T and TAlk. This directly incorporated the inherent nonlinearities of the carbonate system, in a completely mechanistic manner. The model's empirical coefficients were determined for a target study area of the central North American Pacific continental margin (22-50°N, within 370 km of the coastline), by optimally reproducing a set of historical observations paired with satellite data. The model-predicted pCO2 agreed with the highly variable observations with a root mean squared (RMS) deviation of <20 ?atm, and with a correlation coefficient of >0.8 (r = 0.81; r2 = 0.66). This level of accuracy is a significant improvement relative to that of simpler models that did not resolve the biogeochemical sub-regions or that relied on linear dependences on input parameters. Air-sea fluxes based on these pCO2 predictions and satellite-based wind speed measurements suggest that the region is a ˜14 Tg C yr-1 sink for atmospheric CO2 over the 1997-2005 period, with an approximately equivalent uncertainty, compared with a ˜0.5 Tg C yr-1 source predicted by a recent bin-averaging and interpolation-based estimate for the same area.

Hales, Burke; Strutton, Peter G.; Saraceno, Martin; Letelier, Ricardo; Takahashi, Taro; Feely, Richard; Sabine, Christopher; Chavez, Francisco

2012-09-01

146

The Economic Potential of Terrestrial Impact Craters  

Microsoft Academic Search

Like concentrations of economic resources, terrestrial impact structures are the result of relatively rare geologic events. Economic resources occur in a number of terrestrial impact structures. After providing a context by briefly summarizing the salient points of the terrestrial impact record and the characteristics of impact craters, the relationship between impact craters and economic resources is explored. Approximately 25% of

R. A. F. Grieve; V. L. Masaitis

1994-01-01

147

On communications with extra-terrestrial or alien intelligences  

Microsoft Academic Search

The discussion deals with two questions: assuming a signal has been detected, does the signal contain a message. If so, how can it be deciphered. The concept of the message as a statistical variate is explained. When the suspected sequence of elements is examined for randomness, if any departure from randomness is found, the presence of a message is indicated.

R. P. Haviland

1975-01-01

148

Time-Bounded Kolmogorov Complexity May Help in Search for Extra Terrestrial Intelligence (SETI)  

Microsoft Academic Search

One of the main strategies in Search for Extra Terrestrial Intelligence (SETI) is trying to overhearcommunications between advanced civilizations. However, there is a (seeming) problem with this approach:advanced civilizations, most probably, save communication expenses by maximally compressingtheir messages, and the notion of a maximally compressed message is naturally formalized as a messagex for which Kolmogorov complexity C(x) is close to

M. Schmidt

1999-01-01

149

Alien Terrestrial Invertebrates of Europe  

Microsoft Academic Search

Unlike other groups of animals and plants, no checklist of alien terrestrial invertebrates was available in any of the European\\u000a countries until recently. Since 2002, such checklists were successively provided by Austria (Essl and Rabitsch 2002), Germany\\u000a (Geiter et al. 2002), the Czech Republic (Šefrová and Lašt? vka 2005), Scandinavia (NOBANIS 2007), the United Kingdom (Hill\\u000a et al. 2005), Switzerland

Alain Roques; Wolfgang Rabitsch; Jean-Yves Rasplus; Carlos Lopez-Vaamonde; Wolfgang Nentwig; Marc Kenis

150

Cadaver decomposition in terrestrial ecosystems  

Microsoft Academic Search

A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an\\u000a intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg\\u000a of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected\\u000a microsere. Here

David O. Carter; David Yellowlees; Mark Tibbett

2007-01-01

151

A robust TEC depletion detector algorithm for satellite based navigation in Indian zone and depletion analysis for GAGAN  

NASA Astrophysics Data System (ADS)

Equatorial plasma bubble (EPB) and associated plasma irregularities are known to cause severe scintillation for the satellite signals and produce range errors, which eventually result either in loss of lock of the signal or in random fluctuation in TEC, respectively, affecting precise positioning and navigation solutions. The EPBs manifest as sudden reduction in line of sight TEC, which are more often called TEC depletions, and are spread over thousands of km in meridional direction and a few hundred km in zonal direction. They change shape and size while drifting from one longitude to another in nighttime ionosphere. For a satellite based navigation system, like GAGAN in India that depends upon (i) multiple satellites (i.e. GPS) (ii) multiple ground reference stations and (iii) a near real time data processing, such EPBs are of grave concern. A TEC model generally provides a near real-time grid based ionospheric vertical errors (GIVEs) over hypothetically spread 5x5 degree latitude-longitude grid points. But, on night when a TEC depletion occurs in a given longitude sector, it is almost impossible for any system to give a forecast of GIVEs. If loss-of-lock events occur due to scintillation, there is no way to improve the situation. But, when large and random depletions in TEC occur with scintillations and without loss-of-lock, it affects low latitude TEC in two ways. (a) Multiple satellites show depleted TEC which may be very different from model-TEC values and hence the GIVE would be incorrect over various grid points (ii) the user may be affected by depletions which are not sampled by reference stations and hence interpolated GIVE within one square would be grossly erroneous. The most general solution (and the far most difficult as well) is having advance knowledge of spatio-temporal occurrence and precise magnitude of such depletions. While forecasting TEC depletions in spatio-temporal domain are a scientific challenge (as we show below), operational systems require an immediate solution to attack this problem. Hence, an alternative approach is chosen in which TEC-depletions are ignored for GIVE estimation. This approach requires further attention to accommodate it in the processing software for a near real time solution for the concerned user in Indian zone. But, nonetheless, as a prime concern, to precluding a particular satellite-link affected by TEC depletion, a reference receiver or user requires an algorithm that can compute the TEC and detect the depletion in TEC in near real time. To answer it, a novel TEC depletion detector algorithm and software has been developed which can be used for any SBAS in India. The algorithm is initially tested for recorded data from ground based dual frequency GPS receivers of GAGAN project. Data from 18-20 stations with 30 second sampling interval was obtained for year 2004 and 2005. The algorithm has been tuned to Indian ionosphere and show a great success in detecting TEC depletions with minimum false alarm. This is because of a specific property of this algorithm that it rejects the smooth fall in TEC in post sunset ionosphere. The depletions in TEC are characterized by a sudden fall and immediate recovery in level of TEC for a given line of sight. Since our algorithm extracts only such signatures and hence minimize the false alarms it may reduce burden on operational systems. We present this algorithm in detail. Another important facet of this algorithm is about its scientific use in automatic analysis of large amount of continuous GPS data. We have analyzed the aforementioned data by a MATLAB based script and obtained significant statistical results. The temporal duration and depth of TEC depletions is obtained for all over Indian region which provide a new insight over the phenomenon called EPBs and TEC depletions.

Dashora, Nirvikar

2012-07-01

152

A Newly Distributed Satellite-based Global Air-sea Surface Turbulent Fluxes Data Set -- GSSTF2b  

NASA Astrophysics Data System (ADS)

Accurate sea surface turbulent flux measurements are crucial to understanding the global water and energy cycle changes. Remote sensing is a valuable tool for global monitoring of these flux measurements. The GSSTF (Goddard Satellite-based Surface Turbulent Fluxes) algorithm was thus developed and applied to remote sensing research and applications. The recently revived and produced daily global (1ox1o) GSSTF2b (Version-2b) dataset (July 1987-December 2008) is currently under processing for an official distribution by NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) due by the end of this month (September, 2010). Like its predecessor product GSSTF2, GSSTF2b is expected to provide the scientific community a longer-period and useful turbulent surface flux dataset for global energy and water cycle research, as well as regional and short period data analyses. We have recently been funded by the NASA/MEaSUREs Program to resume processing of the GSSTF with an objective of continually producing an up-to-date uniform and reliable dataset of sea surface turbulent fluxes, derived from improved input remote sensing data and model reanalysis, which would continue to be useful for global energy and water flux research and applications. The daily global (1ox1o) GSSTF2b dataset has lately been produced using upgraded and improved input datasets such as the Special Sensor Microwave Imager (SSM/I) Version-6 (V6) product (including brightness temperature [Tb], total precipitable water [W], and wind speed [U]) and the NCEP/DOE Reanalysis-2 (R2) product (including sea skin temperature [SKT], 2-meter air temperature [T2m], and sea level pressure [SLP]). The input datasets previously used for producing the GSSTF2 product were the SSM/I Version-4 (V4) product and the NCEP Reanalysis-1 (R1) product. The newly produced GSSTF2b was found to generally agree better with available ship measurements obtained from several field experiments in 1999 than its counterpart GSSTF2 in all the three flux components - latent heat flux (LHF), sensible heat flux (SHF), and wind stress (WST). The major meteorological input variables such as wind speed, total & bottom-layer precipitable water (W & WB), and surface air & sea humidity (Qa & Qs) of GSSTF2b and GSSTF2 were also examined and compared for global and regional scales in this study. One of our major findings is that the SSM/I Tb (i.e., Tb19v and Tb22v), which was used to retrieve WB and thus Qa, has an indirect impact on the global tendency/trend found in our LHF products. More features and applications (e.g., the ENSO scenarios and the monsoon systems) of GSSTF2b will be presented, along with a brief demonstration of accessing the dataset on the designated website of GES DISC in the meeting.

Shie, C.; Nelkin, E.; Ardizzone, J.; Savtchenko, A.; Chiu, L. S.; Adler, R. F.; Lin, I.; Gao, S.

2010-12-01

153

Downscaling Satellite-based Passive Microwave Observations Using the Principle of Relevant Information and Auxiliary High Resolution Remote Sensing Products  

NASA Astrophysics Data System (ADS)

Hydrometeorological models simulate the atmospheric and hydrological processes at scales of 1- 10 km that are significantly influenced by the local and regional availability of soil moisture. Microwave observations at frequencies < 10 GHz are highly sensitive to changes in near-surface moisture and have been widely used to retrieve soil moisture information. While satellite-based active microwave observations are available at spatial resolutions of hundreds of meters, with temporal resolutions of several weeks, passive observations are obtained only at tens of kilometers with temporal resolutions of sub daily to 2-3 days. The European Space Agency-Soil Moisture and Ocean Salinity (ESA-SMOS) and the near-future NASA-Soil Moisture Active Passive (SMAP) missions will provide unprecedented passive microwave observations of brightness temperatures (TB) at the L-band frequency of 1.4 GHz. These products will be available at spatial resolutions of about 40-50 km and need to be downscaled to 1 km to merge them with models for data assimilation and to study the effects of land surface heterogeneity such as dynamic vegetation conditions. Very few studies have directly downscaled coarse-resolution TB observations to match model scales. Since downscaling is an ill-posed problem, additional information is required at the fine scales and some studies have leveraged auxiliary high-resolution remote sensing (RS) products in downscaling TB. Most of the above studies involve a) physical models that are computationally intensive when extended to global scales, or b) multi-scale algorithms that impose hierarchical models on TB assuming spatial homogeneity, or c) statistical algorithms that are based on second-order statistics such as variances and correlations. These approaches are therefore sub-optimal when applied to the real data or extended to regional/global scales. Optimal downscaling requires computationally-efficient algorithms that retain information from higher-order moments, especially under heterogeneous land surface conditions. Novel transformation functions leveraging physical relationships and recent advances in signal processing techniques can be used to transform information from high-resolution RS products into TB. In this study, a downscaling methodology was developed using the Principle of Relevant Information (PRI) to downscale observations of TB from 50 km to 200 m using observations of land surface temperature, leaf area index, and land cover at 200 m. The PRI provides a hierarchical decomposition of image data that is optimal in terms of the transfer of information across scales and is therefore a better alternative to methods that use second-order statistics only. Non-parametric probability density functions and Bayes' rule was used to transform information from the RS products into TB. An Observing System Simulation Experiment was developed under heterogeneous and dynamic vegetation conditions to generate synthetic observations at 200m to evaluate the downscaling methodology and the transformation functions.

Nagarajan, K.; Judge, J.; Principe, J.

2011-12-01

154

Arsenic Speciation of Terrestrial Invertebrates  

SciTech Connect

The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine sites and one background site in Nova Scotia, Canada. Total arsenic concentrations, determined by inductively coupled plasma mass spectrometry (ICP-MS), were dependent upon the classification of invertebrate. Arsenic species were determined by high-performance liquid chromatography (HPLC) ICP-MS and X-ray absorption spectroscopy (XAS). Invertebrates were found by HPLC ICP-MS to contain predominantly arsenite and arsenate in methanol/water extracts, while XAS revealed that most arsenic is bound to sulfur in vivo. Examination of the spatial distribution of arsenic within an ant tissue highlighted the differences between exogenous and endogenous arsenic, as well as the extent to which arsenic is transformed upon ingestion. Similar arsenic speciation patterns for invertebrate groups were observed across sites. Trace amounts of arsenobetaine and arsenocholine were identified in slugs, ants, and spiders.

Moriarty, M.M.; Koch, I.; Gordon, R.A.; Reimer, K.J. ((Simon)); ((Royal))

2009-07-01

155

A Satellite Based Assessment of the Impact of Urban Sprawl on Carbon Balance (NPP) of the United States  

NASA Astrophysics Data System (ADS)

For the first time, diurnal observations from two Earth imaging satellites were used to measure the extent of urban sprawl and estimate the photosynthetic capacity of the land surface inside and outside urbanized areas and assess the impact of urbanization on the terrestrial carbon cycle. Night-time data from the Defense Meteorological Satellite Program's Operational Linescan System were used to map urban areas and monthly maximum NDVI values from1-km AVHRR data were used with the Carnegie Ames Stanford Approach biophysical model to estimate net primary production (NPP). Seasonal profiles of NPP for urban and non-urban areas describe a variable effect on production depending upon the prevailing local climate and a strong urban "warming" signal can be seen. A comparison between a simulated "pre-urban" landscape and current conditions indicates that urbanization has reduced the productivity of the US land surface by about 0.012 PgC per year - about 0.5% of the estimated annual total. In terms of human requirements, this loss translates to enough energy to feed 105 million persons per year. The impact on biological systems therefore may be significant.

Imhoff, M. L.; Lawrence, W.; Bounoua, L.; Stutzer, D.; Tucker, C. J.; Ricketts, T.; Drob, K. M.

2001-12-01

156

MODIS Satellite-based particulate matter monitoring in Northern Italy: towards a MACC core-downstream processing chain test-case  

NASA Astrophysics Data System (ADS)

Satellite remote sensing of both trace gas constituents and Particulate Matter (PM) can be profitably exploited in the Air Quality field by combining satellite observations with regional meteorological modelling and ground-based measurements. With regard to this, the capability of MODIS sensors (Terra and Aqua/NASA platforms) to retrieve aerosol optical properties has been used in a semi-empirical approach to estimate PM content at the ground over a domain containing whole Northern Italy. Daily maps of satellite-based PM2.5 concentrations over Northern Italy have been derived. Daily estimates and monthly averaged values have been compared to in-situ PM2.5 sampling providing a good agreement, with the MODIS-based concentrations tending to underestimate the values by at most 20%. These findings represent the direct outcome of the prototype Satellite-based Particulate Matter demonstration service developed in strict synergy between QUITSAT project (2006-2009) - funded by the Italian Space Agency - and PROMOTE project (2006-2009) - supported by the European Space Agency. In both projects a significant role has been played by regional environmental agencies - ARPA - of 3 regions located in the Po valley area (Emilia Romagna, Piedmont and Lombardia) acting as Users and analyzing the quality of the achieved satellite-based products and service performances. Relying on the experience achieved within these projects, ARPA users have expressed the interest in providing requirements, following the development, and testing the core-downstream-end user service chain in O-INTERFACE MACC subproject funded under the EU 7th Framework Program and the forthcoming EU 7th FP PASODOBLE project.

di Nicolantonio, Walter; Cacciari, Alessandra; Tiesi, Alessandro; Tomasi, Claudio

2010-05-01

157

Recent geographic variations in terrestrial carbon cycle based on new production efficiency model  

NASA Astrophysics Data System (ADS)

The terrestrial carbon budget must be understood more accurately for the prediction of future changes in climate and carbon cycle. The goal of this study is to estimate spatial and temporal patterns of the carbon fluxes more accurately using the newly developed terrestrial biosphere model and satellite data. Our model consists of terrestrial carbon cycle and hydrology submodels. An advantage is a new approach in the LUE (Light Use Efficiency) concept, which calculates temperature and water stress factor in LUE model from a photosynthetic model and stomatal conductance formulation. In carbon cycle model, GPP is calculated from the LUE concept and satellite-based fPAR dataset. The soil carbon cycle model is based on CENTURY model with optimized water and temperature factor. Hydrological submodel is based on BIOME3, calculating ET is used by Penman-Monteith method. The model was run for 18 years (1982-1999) on a global scale, and we simulated the geographic distributions of the terrestrial carbon fluxes. We have checked simulated vegetation growth limiting factor with stress factor of MODIS NPP algorithm. Large differences were found in the northern mid and high latitude forests because soil moisture stress is not incorporated into MODIS NPP algorithm. Although responses of stress factors in MODIS NPP algorithm are mostly similar to our theoretically based one, our model works well in the soil moisture limited regions. Global total NPP was estimated at 61.7GtC/yr, and total NEP variations are strongly related with ENSO. Validation using measured values from the GPPDI database showed that our NPP estimation was within a reasonable range. The temporal patterns of the terrestrial carbon flux showed that NPP increased in the northern middle/high latitudes, central Africa, and India. In contrast, NPP decreased in the south Amazon region, the middle latitudes of the southern hemisphere, a part of North America, and Southeast Asia. Sensitivity analysis indicated that NPP variations were largely affected by fAPAR, solar radiation, temperature, and precipitation variations. Our new model was shown to be an appropriate tool to estimate the spatial and temporal patterns of the terrestrial carbon fluxes.

Sasai, T.; Ichii, K.; Yamaguchi, Y.

2003-12-01

158

MODIS-Derived Terrestrial Primary Production  

Microsoft Academic Search

\\u000a Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems\\u000a not only create environments suitable for human habitation, but also provide materials essential for survival, such as food,\\u000a fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of all the acronyms\\u000a is available in the

Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

159

EHF space systems: Experimental missions for broadband communications  

Microsoft Academic Search

In the last years scientific community has been witness of the growing interest in global EHF satellite systems for broadband communications; these systems can help national and regional telecommunications service operators to provide broadband communications in areas not adequately served by terrestrial systems. In this paper main EHF satellite missions are presented, outlining challenges and future perspectives.

Marina Ruggieri; E rnestina Cianca; Tommaso Rossi; Marco Lucente; Cosimo Stallo; Giuseppe Codispoti; Lamberto Zuliani

2009-01-01

160

US Air Force communications in Desert Storm  

Microsoft Academic Search

The US Central Command Air Forces' (USCENTAF) communications network for Operations Desert Shield and Desert Storm is described. The Central Command Air Forces network utilized 27 SatCom terminals, 27 automatic switches, and 27 terrestrial links and had the responsibility of providing air traffic services across six countries at 24 locations handling 350000 flight operations. The system complexity and air traffic

D. D. McKenzie

1992-01-01

161

Propagation prediction models for wireless communication systems  

Microsoft Academic Search

A comprehensive review of the propagation prediction models for terrestrial wireless communication systems is presented in this paper. The classic empirical models are briefly described and the focus is placed on the application of ray-tracing techniques to the development of deterministic propagation models. Schemes to increase the computational efficiency and accuracy are discussed. Traditional statistical models are also briefly reviewed

Magdy F. Iskander; Zhengqing Yun

2002-01-01

162

Cadaver decomposition in terrestrial ecosystems  

NASA Astrophysics Data System (ADS)

A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.

Carter, David O.; Yellowlees, David; Tibbett, Mark

2007-01-01

163

The Emergence of Terrestrial Hydrometeorology  

NASA Astrophysics Data System (ADS)

In the Encyclopaedia of Atmospheric Sciences and Astrogeology Langbein (1967) defined hydroclimatology as "the study of the influence of climate upon the waters of the land", and hydrometeorology is study of short term processes and phenomena within this climatology. But this definition is now outdated because it implies too passive a role for land surface influences on the overlying atmosphere. Over the subsequent decades research has demonstrated that proper understanding of land surface hydrology requires investigations of the hydrometeorological processes that couple terrestrial surfaces and the atmosphere. These investigations include the development and calibration of land surface models; mesoscale field experiments, that considered heterogeneity in land surface cover and investigated their aggregate representation; studies of how coupling processes relate to the concept of potential evaporation, and how estimates of irrigated crop water requirement can be updated; application of remotely sensed data and the simplifying benefits of in-plant linkages between water vapor and carbon exchange mechanisms; and the potential benefits of now-feasible area-average soil moisture measurement. This lecture reviews such investigations in the area of terrestrial hydrometeorology with some emphasis on those that have involved the speaker's participation, and argues for the creation for a new branch of scientific education focused on the subject area that lies at the interface between hydrology and meteorology.

Shuttleworth, W. J.

2011-12-01

164

Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment  

Microsoft Academic Search

Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the

Damjana Drobne

1997-01-01

165

Long-term solar-terrestrial observations.  

National Technical Information Service (NTIS)

In the fall of 1985, the Committee on Solar-Terrestrial Research (CSTR) created a panel to study the requirements for long-term monitoring and archiving of solar-terrestrial data. The panel comprised specialists in all four areas that constitute solar-ter...

1988-01-01

166

ECOREGIONAL ASSESSMENT EQUATORIAL PACIFIC: TERRESTRIAL COMPONENT  

Microsoft Academic Search

The main objective of the Terrestrial component of this Ecoregional Assessment is to identify priority conservation sites within the terrestrial ecosystems in the Equatorial Pacific region. With this purpose, a portfolio of sites was identified, including information available for decision makers and stake-holders for natural resources, such as biodiversity, soils, vegetation cover and others. The methodology, developed by The Nature

G. Pinos

167

Exploring The Detectability of Terrestrial Exoplanet Characteristics  

Microsoft Academic Search

Of the 400+ extrasolar planets that have been discovered to date, the vast majority are massive gas giants. This is largely due to the inherent difficulty of detecting terrestrial planets, which are small and faint by comparison. Both NASA and ESA have proposed mission concepts for space-based observatories (Terrestrial Planet Finder [TPF] and Darwin, respectively) capable of detecting these planets

Nicole Evans; V. S. Meadows; S. D. Domagal-Goldman

2011-01-01

168

Does terrestrial epidemiology apply to marine systems?  

Microsoft Academic Search

Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly trans- ferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent

Hamish I. McCallum; Armand Kuris; C. Drew Harvell; Kevin. D. Lafferty; Garriet W. Smith; James Porter

2004-01-01

169

Thin Film Solar Cells for Terrestrial Applications.  

National Technical Information Service (NTIS)

The goals of the project are to develop a terrestrial version of the CdS thin film solar cell that is demonstrably amenable to low cost mass production, and to establish data on the lifetime of such cells under the expected conditions of terrestrial use. ...

F. A. Shirland W. J. Biter E. W. Greeneigh T. P. Brody

1975-01-01

170

The geophysical signature of terrestrial impact craters  

Microsoft Academic Search

A major tool in the initial recognition and study of terrestrial impact craters, ?20% of which are buried beneath postimpact sediments, is geophysics. The general geophysical character of terrestrial impact craters is compiled and outlined with emphasis on its relation to the impact process and as an aid to the recognition of additional impact craters. The most common and conspicuous

M. Pilkington; R. A. F. Grieve

1992-01-01

171

Rapid Warming of the World's Lakes: A Global Assessment of Recent Lake Temperature Trends Using In Situ and Satellite-Based Records  

NASA Astrophysics Data System (ADS)

Recent studies have revealed significant warming of lakes throughout the world, and the observed rate of lake warming is - in many cases - more rapid than that of the ambient air temperature. These large changes in lake temperature have profound implications for lake hydrodynamics, productivity, and biotic communities. The scientific community is just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. Although many in situ lake temperature records are available, only a few encompass long time periods. Most datasets are collected by individual investigators, have varying sampling protocols, and do not have extensive geographic or temporal coverage. Remote sensing methods, on the other hand, have been increasingly used to characterize global trends in lake surface temperature, and they provide an invaluable counterpart to in situ measurements. However, the existing satellite records do not extend as far back in time as some of the longer in situ datasets, and remotely sensed measurements capture only surface temperature, rather than vertical profiles. In this study, we present initial results from an international collaborative effort to synthesize global records of lake temperature from in situ and satellite-based measurements. Surface water temperature data are analyzed from over 120 lakes distributed across 40 countries. Data from 20 of the lakes are based on in situ measurements, while the remaining 100+ lake temperature records are obtained from satellite-based methods. We focus primarily on mean summer water temperatures for the 25-year period 1985-2009, as this provides a common time period with the largest amount of available data. Linear regression analysis reveals that 65% of the lakes in the database are experiencing significant summertime warming (p < 0.1), with another 30% warming at a rate that is not statistically significant. Only 5% of the lakes in the database show cooling trends (none of which are significant). The in situ and satellite-based measurements show a very similar distribution of water temperature trends among lakes, with a mean value of approximately +0.5 °C/decade and standard deviation of +/-0.3 °C/decade (maximum = +1.0 °C/decade). We also examine a variety of external controlling factors (e.g., air temperature, solar radiation, latitude, and lake depth) to understand the physical mechanisms associated with the global and regional patterns of lake warming.

Lenters, J. D.; Adrian, R.; Allan, M.; de Eyto, E.; Hamilton, D. P.; Hook, S.; Izmestyeva, L.; Kraemer, B.; Kratz, T.; Livingstone, D.; Mcintyre, P.; Montz, P.; Noges, P.; Noges, T.; O'Reilly, C.; Read, J.; Sandilands, K.; Schindler, D.; Schneider, P.; Silow, E.; Straile, D.; Van Cleave, K.; Zhdanov, F.

2011-12-01

172

Methane production in terrestrial arthropods  

SciTech Connect

The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

Hackstein, J.H.P.; Stumm, C.K. (Catholic Univ. of Nijmegen (Netherlands))

1994-06-07

173

Solar-Terrestrial Ontology Development  

NASA Astrophysics Data System (ADS)

The development of an interdisciplinary virtual observatory (the Virtual Solar-Terrestrial Observatory; VSTO) as a scalable environment for searching, integrating, and analyzing databases distributed over the Internet requires a higher level of semantic interoperability than here-to-fore required by most (if not all) distributed data systems or discipline specific virtual observatories. The formalization of semantics using ontologies and their encodings for the internet (e.g. OWL - the Web Ontology Language), as well as the use of accompanying tools, such as reasoning, inference and explanation, open up both a substantial leap in options for interoperability and in the need for formal development principles to guide ontology development and use within modern, multi-tiered network data environments. In this presentation, we outline the formal methodologies we utilize in the VSTO project, the currently developed use-cases, ontologies and their relation to existing ontologies (such as SWEET).

McGuinness, D.; Fox, P.; Middleton, D.; Garcia, J.; Cinquni, L.; West, P.; Darnell, J. A.; Benedict, J.

2005-12-01

174

Contrasting coloration in terrestrial mammals  

PubMed Central

Here I survey, collate and synthesize contrasting coloration in 5000 species of terrestrial mammals focusing on black and white pelage. After briefly reviewing alternative functional hypotheses for coloration in mammals, I examine nine colour patterns and combinations on different areas of the body and for each mammalian taxon to try to identify the most likely evolutionary drivers of contrasting coloration. Aposematism and perhaps conspecific signalling are the most consistent explanations for black and white pelage in mammals; background matching may explain white pelage. Evidence for contrasting coloration is being involved in crypsis through pattern blending, disruptive coloration or serving other functions, such as signalling dominance, lures, reducing eye glare or in temperature regulation has barely moved beyond anecdotal stages of investigation. Sexual dichromatism is limited in this taxon and its basis is unclear. Astonishingly, the functional significance of pelage coloration in most large charismatic black and white mammals that were new to science 150 years ago still remains a mystery.

Caro, Tim

2008-01-01

175

The evolution of global mobile communications  

NASA Astrophysics Data System (ADS)

A long term, global viewpoint is presented on the subject of communications access which may be the key to resolving many of the world's current requirements for developing a truly global, ubiquitous mobile/personal voice and data communications capability. The solutions are multi disciplinary, some using terrestrial techniques, some by satellite, but both using a variety of technologies and techniques. In the area of satellite communications, the focus is on inexpensive, efficient antennas, high gain spacecraft amplifiers and efficient power and bandwidth modulation techniques including high performance, low bit rate voice codecs. Terrestrially, many of the same technologies apply to cellular telephone systems. A key issue is the electromagnetic spectrum and its utilization efficiency, especially if the popularity of cellular telephones is repeated in the development of mobile satellite systems. Integration of diverse systems depends on formulating a framework that will allow systems to be interoperable by specifying logical interfaces among most or all evolving niche systems.

Spolsky, A. I.; Brasic, J. R.

176

Communications Pretesting.  

National Technical Information Service (NTIS)

The majority of social development programs around the world stand to benefit from communicating their activities through the mass media. Most program administrators will invest in communication that will effectively reach a target population but will avo...

1978-01-01

177

Speech Communication.  

ERIC Educational Resources Information Center

|Presented in this book is a view of speech communication which enables an individual to become fully aware of his or her role as both initiator and recipient of messages. Communication is treated broadly with emphasis on the understanding and skills relating to various types of speech communication across the broad spectrum of human…

Brooks, William D.

178

Ripple Communication.  

ERIC Educational Resources Information Center

Discusses how surface-dwelling animals use the water surface as a mode of communication by making ripple signals while they swim about. Provides information about surfaces and surface waves, ripple communication in water striders, ripple signal characteristics, sensing and orienting, other modes of communication, and evolution of ripple…

Wilcox, R. Stimson

1980-01-01

179

Cultural Communications.  

ERIC Educational Resources Information Center

|It is too often taken for granted that the communication process with culturally different children takes place as readily as it might with children from Anglo cultures. Most teachers receive training in verbal and formal communication skills; children come to school with nonverbal and informal communication skills. This initially can create…

Armas, Jose

180

Interracial Communication.  

ERIC Educational Resources Information Center

|Designed to introduce communicators to the factors influencing them interracial and interethnic interaction, this study attempts to explain the dynamics of interracial communication by offering descriptions of various interracial interaction situations and possible reasons for the existence of problems in interracial communication. The first…

Rich, Andrea L.

181

[Dark respiration of terrestrial vegetations: a review].  

PubMed

The source and sink effect of terrestrial plants is one of the hotspots in terrestrial ecosystem research under the background of global change. Dark respiration of terrestrial plants accounts for a large fraction of total net carbon balance, playing an important role in the research of carbon cycle under global climate change. However, there is little study on plant dark respiration. This paper summarized the physiological processes of plant dark respiration, measurement methods of the dark respiration, and the effects of plant biology and environmental factors on the dark respiration. The uncertainty of the dark respiration estimation was analyzed, and the future hotspots of related researches were pointed out. PMID:24066565

Sun, Jin-Wei; Yuan, Feng-Hui; Guan, De-Xin; Wu, Jia-Bing

2013-06-01

182

Communication: Health Communication: Health Professionals ...  

Center for Biologics Evaluation and Research (CBER)

Text VersionPage 1. Communication: Health Communication: Health Professionals and Consumers Professionals and Consumers Presented by Presented by ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

183

Carbon stabilization on terrestrial landscapes  

NASA Astrophysics Data System (ADS)

While terrestrial climate models view C budgets through time-slices of environmental reconstructions, yet during climate transitions, pervasive geomorphic response to climate likely dictate the direction and magnitude of C exchange. Geomorphic processes therefore act as disturbance events that have the potential to create large feedbacks to climate regulation through carbon burial or carbon release. Quantifying the rates of carbon accumulation in various types of deposits allows us to assess intensities of C burial, whereas the spatial extent and timing of geomorphic processes allows us to quantify the net impact on atmospheric CO2 budgets. Mechanisms and forms of C that are buried or stored lend insights into the longevity of these geomorphic events that dictate land-atmosphere C exchange. Chronosequences of fluvial, loess, and coastal deposits dated by various chronologic tools were used to calculate carbon intensities, or accumulation rates, into soil and deep sediment. Vertical cores of peat and permafrost provide such rates through direct aging of organic carbon preserved in the cores. Rates of input to soil and surface sediment varied by 4 orders of magnitude, which reflects variations in both plant production and decomposition over various timescales of decades to millennia. In general, shallow and shorterm rates are higher than deep, longterm rates. Based on the soil property that best predicts C storage and turnover, we hypothesize different mechanisms of stabilization for selected soil profiles: For example clay content, free iron oxides, freezing temperatures were key in C stabilization within the upper meter of Alfisols, Ultisols, and Cryosols, respectively.

Harden, Jennifer W.; Lawrence, Corey; Trumbore, Susan; O'Donnell, Jonathan; Vanoost, Kristof

2010-05-01

184

Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment  

SciTech Connect

Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the digestive glands. These responses are able to provide accurate indications of sublethal toxicity. Toxicity tests with terrestrial isopods could be much more reliable through the use of positive controls. A positive control with a reference toxicant could also be supplemented by a reference endpoint. The most suitable reference endpoint is change of food consumption rate. Toxicity testing with terrestrial isopods is a very promising method for fast, routine, and inexpensive laboratory determination of the relative toxicities of chemicals in the terrestrial environment.

Drobne, D. [Univ. of Ljubljana (Slovenia). Dept. of Biology

1997-06-01

185

The NASA-Lewis Terrestrial Photovoltaics Program.  

National Technical Information Service (NTIS)

Research and technology efforts on solar cells and arrays having relevance to terrestrial uses are outline. These include raising cell efficiency, developing the FEP-covered module concept, and exploring low cost cell concepts. Solar cell-battery power sy...

D. T. Bernatowicz

1973-01-01

186

High Efficiency, Long Life Terrestrial Solar Panel.  

National Technical Information Service (NTIS)

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evalua...

T. Chao S. Khemthong R. Ling S. Olah

1977-01-01

187

Data of Solar Terrestrial Interest, August 1971.  

National Technical Information Service (NTIS)

Routine observations of solar-terrestrial interest, collected at the following stations of the Scientific Group for Space Research are presented for August 1971: (1) Agia Paraskevi ionospheric station temporarly housed at the Democritus Nuclear Research C...

D. J. Ilias D. P. Elias

1971-01-01

188

Data of Solar Terrestrial Interest, July 1971.  

National Technical Information Service (NTIS)

Routine observations of solar-terrestrial interest, collected at the following stations of the Scientific Group for Space Research are presented for July 1971: (1) Agia Paraskevi ionospheric station temporarly housed at the Democritus Nuclear Research Cen...

D. J. Ilias D. P. Elias

1971-01-01

189

Preliminary Testing of Mycoleptodiscus terrestris Formulations.  

National Technical Information Service (NTIS)

This technical note reports preliminary results of bioassays of dried formulations of Mycoleptodiscus terrestris (Gerd.) Ostazeski (Mt) for management of the submersed macrophyte, Hydrilla verticillata (L.f.) Royle (hydrilla).

J. F. Shearer

2009-01-01

190

Supporting Tools of Solar-Terrestrial Science.  

National Technical Information Service (NTIS)

Solar-terrestrial science is pursued by individuals and teams of workers situated in academia, research institutes, industry, and government laboratories. Progress in the field is made in various ways, but publication of results in scientific journals is ...

1989-01-01

191

New Pest Response Guidelines: Temperate Terrestrial Gastropods.  

National Technical Information Service (NTIS)

Use New Pest Response Guidelines: Temperate Terrestrial Gastropods as a guide when designing a program to detect, monitor, control, contain, or eradicate an infestation of temperate climate pest snails and slugs in the United States and collaborating terr...

2008-01-01

192

Data Base of Terrestrial Impact Structures  

NSDL National Science Digital Library

Database of Terrestrial Impact Structures leads to Natural Resources Canada's interactive global database of impact structures, complete with photographs and summary information. For those interested in learning more about Impact Craters, this is a fine starting point.

1997-01-01

193

Carbon-14 terrestrial ages of Antarctic meteorites  

NASA Astrophysics Data System (ADS)

The carbon-14 terrestrial ages of four Yamato meteorites are measured and compared with the C-14 terrestrial ages of eighteen meteorites from Victoria Land. The youngest Yamato meteorite, Y-75102, is 4300 + or - 1000 yr; the oldest, Y-74459, is 24,000 + or - 2000 yr. The Yamato meteorite site is collecting recent falls, less than 25,000 yr, at a more rapid rate than the Victoria Land sites.

Fireman, E. L.

1983-12-01

194

Parallel Computing for Terrestrial Ecosystem Carbon Modeling  

SciTech Connect

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO{sub 2}. The influence of terrestrial ecosystems on atmospheric CO{sub 2} can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO{sub 2} concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO{sub 2} uptake and respiratory CO{sub 2} release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change impact analysis.

Wang, Dali [ORNL; Post, Wilfred M [ORNL; Ricciuto, Daniel M [ORNL; Berry, Michael [University of Tennessee, Knoxville (UTK)

2011-01-01

195

Antarctic terrestrial biodiversity in a changing world  

Microsoft Academic Search

Recent analyses of Antarctic terrestrial biodiversity data, in combination with molecular biological studies, have created\\u000a a new paradigm that long-term persistence and regional isolation are general features of most of the major groups of Antarctic\\u000a terrestrial biota, overturning the previously widely assumed view of a generally recent colonisation history. This paradigm,\\u000a as well as incorporating a new and much longer

Peter Convey

196

Hazard and risk assessment of chemicals for terrestrial ecosystems.  

PubMed

Risk assessment for terrestrial ecosystems represents a great challenge due to their complexity. Pragmatic approaches, such as independent assessments for soil and 'above soil' organisms, are unrealistic. This communication presents a workable alternative, extending the role of the hazard identification. For each chemical, a set of selected ecological receptors and exposure routes is considered. Terrestrial vertebrates, soil-ground-foliar dwelling invertebrates, plants, and soil micro-organisms, are potential receptors subjected to direct and indirect exposures. Direct exposures cover those related to the emissions during the Life Cycle of the chemical. Indirect exposures focus on those occurring after the emission, related to the fate and behaviour of the molecule in the environment. Direct exposures are regulated by the production-use-disposal patterns. Indirect exposures are regulated by intrinsic (physicochemical, biological) properties. Hazard identification considers the toxicological profile and the exposure potential for each receptor, and selects the key receptors for the assessment. Risk analysis includes, for each receptor, all potential exposure routes and the corresponding timings. Food chain biomagnification is quantified on the basis of toxicokinetic data and a three vertebrate species model, suitable for top-predators and humans. A higher tier approach, considering the lack of homogeneity of the exposure and probabilistic assumptions, can also be conducted. PMID:12505308

Tarazona, J V; Vega, M M

2002-12-27

197

The Compositional Diversity of Extrasolar Terrestrial Planets  

NASA Astrophysics Data System (ADS)

The details of the formation of the terrestrial planets are long-standing questions in the geological, planetary and astronomical sciences, with the discovery of extrasolar planetary systems placing even greater emphasis on these questions. Here we present simulations of the bulk compositions of simulated terrestrial planets in extrasolar planetary systems. These simulations incorporate both giant planet migration into the dynamical simulations and a variety of ices, clathrates and hydrates into the chemical modeling, providing us with a more inclusive view of extrasolar terrestrial planet formation. We find that a diverse range of extrasolar terrestrial planets are produced, ranging from bulk elemental compositions similar to that of Earth to those that are enriched in elements such as C and Si, producing planets with compositions unlike anything we have previously observed. Giant planet migration significantly alters the composition of the final terrestrial planet by redistributing material throughout the system. Simulated terrestrial planets produced within the migration simulations are found to contain larger amounts of Mg-silicate species and hydrous material. These variations in composition will greatly influence planetary processes such as plate tectonics, planetary interior structure and the primary atmospheric composition.

Carter-Bond, J. C.; O'Brien, D. P.

2011-12-01

198

Update on terrestrial ages of Antarctic meteorites  

SciTech Connect

Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

Welten, K C; Nishiizumi, K; Caffee, M W

2000-01-14

199

Enhancing terrestrial ecosystem sciences by integrating empirical modeling approaches  

NASA Astrophysics Data System (ADS)

Strategies to Promote Integrated Experiment-Model Approaches to Terrestrial Ecosystem Study; Bethesda, Maryland, 19-21 March 2012 Field and laboratory experiments and observations, along with models, are foundational approaches to scientific inquiry. Integration of these approaches, however, can be an exceedingly difficult challenge because empiricists and modelers often work in communities separated by cultural differences and communication barriers, reflecting a largely independent evolution of these disciplines. To address this challenge, more than 40 participants gathered for a 3-day workshop to discuss how models can best inform empirical experiments, how data can most effectively inform models, and what strategies can be employed to integrate these two approaches. The workshop was convened with the understanding that such a priori exchange between the empirical and modeling communities can maximize intellectual investments and result in high-quality predictive models and more scientific discovery.

Lee, Hanna; Wullschleger, Stan D.; Luo, Yiqi

2012-06-01

200

THE EFFECT OF CLOUD FRACTION ON THE RADIATIVE ENERGY BUDGET: The Satellite-Based GEWEX-SRB Data vs. the Ground-Based BSRN Measurements  

NASA Astrophysics Data System (ADS)

The NASA GEWEX-SRB (Global Energy and Water cycle Experiment - Surface Radiation Budget) project produces and archives shortwave and longwave atmospheric radiation data at the top of the atmosphere (TOA) and the Earth's surface. The archive holds uninterrupted records of shortwave/longwave downward/upward radiative fluxes at 1 degree by 1 degree resolution for the entire globe. The latest version in the archive, Release 3.0, is available as 3-hourly, daily and monthly means, spanning 24.5 years from July 1983 to December 2007. Primary inputs to the models used to produce the data include: shortwave and longwave radiances from International Satellite Cloud Climatology Project (ISCCP) pixel-level (DX) data, cloud and surface properties derived therefrom, temperature and moisture profiles from GEOS-4 reanalysis product obtained from the NASA Global Modeling and Assimilation Office (GMAO), and column ozone amounts constituted from Total Ozone Mapping Spectrometer (TOMS), TIROS Operational Vertical Sounder (TOVS) archives, and Stratospheric Monitoring-group's Ozone Blended Analysis (SMOBA), an assimilation product from NOAA's Climate Prediction Center. The data in the archive have been validated systemically against ground-based measurements which include the Baseline Surface Radiation Network (BSRN) data, the World Radiation Data Centre (WRDC) data, and the Global Energy Balance Archive (GEBA) data, and generally good agreement has been achieved. In addition to all-sky radiative fluxes, the output data include clear-sky fluxes, cloud optical depth, cloud fraction and so on. The BSRN archive also includes observations that can be used to derive the cloud fraction, which provides a means for analyzing and explaining the SRB-BSRN flux differences. In this paper, we focus on the effect of cloud fraction on the surface shortwave flux and the level of agreement between the satellite-based SRB data and the ground-based BSRN data. The satellite and BSRN employ different measuring methodologies and thus result in data representing means on dramatically different spatial scales. Therefore, the satellite-based and ground-based measurements are not expected to agree all the time, especially under skies with clouds. The flux comparisons are made under different cloud fractions, and it is found that the SRB-BSRN radiative flux discrepancies can be explained to a certain extent by the SRB-BSRN cloud fraction discrepancies. Apparently, cloud fraction alone cannot completely define the role of clouds in radiation transfer. Further studies need to incorporate the classification of cloud types, altitudes, cloud optical depths and so on.

Zhang, T.; Stackhouse, P. W.; Gupta, S. K.; Cox, S. J.; Mikovitz, J. C.; Nasa Gewex Srb

2011-12-01

201

Hyperspectral-LIDAR system and data product integration for terrestrial applications  

NASA Astrophysics Data System (ADS)

This manuscript details the development and validation of a unique forward thinking instrument and methodology for monitoring terrestrial carbon dynamics through synthesis of existing hyperspectal sensing and Light Detection and Ranging (LIDAR) technologies. This technology demonstration is directly applicable to linking target mission concepts identified as scientific priorities in the National Research Council (NRC, 2007) Earth Science Decadal Survey; namely, DESDynI and HyspIRI. The primary components of the Hyperspec-LIDAR system are the ruggedized imaging spectrometer and a small footprint LIDAR system. The system is mounted on a heavy duty motorized pan-tilt unit programmed to support both push-broom style hyperspectral imaging and 3-D canopy LIDAR structural profiling. The integrated Hyperspec-LIDAR sensor system yields a hypserspectral data cube with up to 800 bands covering the spectral range of 400 to 1000 nm and a 3-D scanning LIDAR system accurately measuring the vertical distribution of intercepted surfaces within a range of 150 m with an accuracy of 15 mm. Preliminary field tests of the Hyperspec-LIDAR sensor system were conducted at a mature deciduous mixed forest tower site located at the Smithsonian Environmental Research Center in Edgewater, MD. The goal of this research is to produce integrated science and data products from ground observations that will support satellite-based hybrid spectral/structural profile linked through appropriate models to monitor Net Ecosystem Exchange and related parameters such as ecosystem Light Use Efficiency.

Corp, Lawrence A.; Cheng, Yen-Ben; Middleton, Elizabeth M.; Parker, Geoffrey G.; Huemmrich, K. Fred; Campbell, Petya K. E.

2009-08-01

202

Satellite-Based Observations of Inter-annual Variation of Vegetation Water Content and Productivity in Northern Asia During 1998-2001  

Microsoft Academic Search

The terrestrial biosphere was largely carbon neutral during the 1980s, but became a much stronger net carbon sink in the 1990s. It is also thought that the unusually large carbon sink in the early 1990s can be largely attributed to climate variability. We analyzed multi-temporal images (1-km spatial resolution, 10-day composites) from the SPOT-4 VEGETATION (VGT) sensor over the period

X. Xiao; B. H. Braswell; Q. Zhang; S. Boles; S. Frolking; B. Moore

2002-01-01

203

Early Formation of Terrestrial Crust  

NASA Astrophysics Data System (ADS)

Early (?4.5 Ga) Formation of Terrestrial Crust T.M. Harrison1, A.K. Schmitt1, M.T. McCulloch2, and O.M. Lovera1 1Department of Earth and Space Sciences and IGPP, UCLA, Los Angeles, CA 90095, USA; 2Research School of Earth Sciences, Australian National University, Canberra, A.C.T. 2601 AUSTRALIA Large deviations in ?repsilonHf(T) from bulk silicate Earth seen in >4 Ga detrital zircons from Jack Hills, Western Australia, have been interpreted as reflecting a major differentiation of the silicate Earth at ca. 4.4 to 4.5 Ga. We have expanded the characterization of 176Hf/177Hf (Hf) in Hadean zircons by acquiring a further 116 laser ablation Lu-Hf measurements on 87 grains with ion microprobe 207Pb/206Pb ages up to 4.36 Ga. Most measurements employed concurrent Lu-Hf and 207Pb/206Pb analyses, permitting assessment of the use of ion microprobe data to characterize the age of the volumetrically larger domain sampled by laser drilling. Our new results confirm and extend the earlier observation of significant negative deviations in ?repsilonHf(T) throughout the Hadean, although no positive ?repsilonHf(T) values were documented in this study. These data yields an essentially uniform spectrum of single-stage model ages between 4.54 and 4.20 Ga for extraction of the zircons' protoliths from a chondritic reservoir. We derived the full error propagation expression for a parameter, ?repsilono, which measures the difference of a sample from solar system initial (Hf) (Hfo), and from this conclude that data plotting close to (Hfo), are statistically meaningful and consistent with silicate differentiation at 4.540±0.006 Ga. ?18O and Ti thermometry for these Hadean zircons show little obvious correlation with initial (Hf), consistent with their derivation through fusion of a broad suite of crustal rock types under near water-saturated conditions. Together with the inclusion assemblage and other isotopic and trace element data obtained from these ancient zircons, our results indicate essentially continuous derivation of crust from the mantle from 4.5 to 4.2 Ga, concurrent with recycling into the mantle and internal crustal re-working. These results represent further evidence that by 4.35 Ga, portions of the crust had taken on continental characteristics.

Harrison, T. M.; Schmitt, A. K.; McCulloch, M. T.; Lovera, O. M.

2007-12-01

204

Formation of the terrestrial planets  

NASA Astrophysics Data System (ADS)

The early phases of formation in the inner solar system were dominated by collisions and short-range dynamical interactions among planetesimals. But the later phases, which account for most of the differences among planets, are unsure because the dynamics are more subtle. Jupiter's influence became more important, leading to drastic clearing out of the asteroid belt and the stunting of Mars's growth. Further in, the effect of Jupiter-- both directly and indirectly, through ejection of mass in the outer solar system-- was probably to speed up the process without greatly affecting the outcome. The great variety in bulk properties of the terrestrial bodies indicate a terminal phase of great collisions, so that the outcome is the result of small-N statistics. Mercury, 65 percent iron, appears to be a residual core from a high-velocity collision. All planets appear to require a late phase of high energy impacts to erode their atmospheres: including the Earth, to remove CO2 so that its ocean could form by condensation of water. Consistent with this model is that the largest collision, about 0.2 Earth masses, was into the proto-Earth, although the only property that appears to require it is the great lack of iron in the Moon. The other large differences between the Earth and Venus, angular momentum (spin plus satellite) and inert gas abundances, must arise from origin circumstances, but neither require nor forbid the giant impact. Venus's higher ratio of light to heavy inert gases argues for it receiving a large icy impactor, about 10-6 Earth masses from far out, requiring some improbable dynamics to get a low enough approach velocity. Core formation in both planets probably started rather early during accretion. Some geochemical evidences argue for the Moon coming from the Earth's mantle, but are inconclusive. Large scale melting of the mantle by the giant impact would plausibly have led to stratification. But the "lock-up" at the end of turbulent mantle convection is a trade-off between rates: crystallization of constituents of small density difference versus overall freezing. Also, factors such as differences in melting temperatures and densities, melt compressibilities, and phase transitions may have had homogenizing effects in the subsequent mantle convection.

Kaula, William M.

1994-01-01

205

Soil moisture mapping over West Africa with a 30-min temporal resolution using AMSR-E observations and a satellite-based rainfall product  

NASA Astrophysics Data System (ADS)

An original and simple method to map surface soil moisture over large areas has been developed to obtain data with a high temporal and spatial resolution for the study of possible feedback mechanisms between soil moisture and convection in West Africa. A rainfall estimation product based on Meteosat geostationary satellite measurements is first used together with a simple Antecedent Precipitation Index (API) model to produce soil moisture maps at a spatial resolution of 10×10 km2 and a temporal resolution of 30-min. However, given the uncertainty of the satellite-based rainfall estimation product, the resulting soil moisture maps are not sufficiently accurate. For this reason, a technique based on assimilating AMSR-E C-band measurements into a microwave emission model was developed in which the estimated rainfall rates between two successive AMSR-E brightness temperature (TB) measurements are adjusted by multiplying them by a factor between 0 and 7 that minimizes the difference between simulated and observed TBs. Ground-based soil moisture measurements obtained at three sites in Niger, Mali and Benin were used to assess the method which was found to improve the soil moisture estimates on all three sites.

Pellarin, T.; Tran, T.; Cohard, J.-M.; Galle, S.; Laurent, J.-P.; de Rosnay, P.; Vischel, T.

2009-10-01

206

Communicator, 1997.  

ERIC Educational Resources Information Center

|The CAG "Communicator" focus is on serving gifted students in California. This document consists of the four issues of "communicator" issued during 1997. Featured articles include: (1) "The Gifted Student At Risk. It Can't Be True" (Judy Roseberry); (2) "Tech Net-Technology and At-Risk Students" (Judy Lieb); (3) "Reviving Ophelia: Saving the…

Bortolussi, Vicki, Ed.

1997-01-01

207

Communicating up  

ERIC Educational Resources Information Center

|Chief communicators at many U.S. institutions are interested in forging closer ties with governing boards. Proponents say such relationships can increase board trust and confidence in communicators before a crisis occurs, making it easier to manage the institution's reputation and limit negative publicity when one does. At some institutions, such…

Lum, Lydia

2013-01-01

208

Communication Notebook.  

ERIC Educational Resources Information Center

|A wide variety of internal and external communication methods used by the Piqua City School District (Ohio) are described. A philosophy statement is followed by descriptions of the roles of the board of education, the community, the teachers, the superintendent, and the media in an effective communications program. Among the 41 external…

Bachman, Duane

209

An overview of the OmniTRACS - The first operational two-way mobile Ku-band satellite communications system  

NASA Astrophysics Data System (ADS)

A two-way mobile Ku-band satellite-based communications system is presented, which has a position reporting capability integrated into a mobile terminal, allowing automatic transmission of LORAN-C derived position information. The system and its service capabilities are described, including the mobile satellite terminal and network management facility. The possible applications of the system are outlined, including applications in transportation, vehicle location, public safety, and public utilities.

Jacobs, Irwin M.

1989-12-01

210

Supporting tools of solar-terrestrial science  

NASA Astrophysics Data System (ADS)

Solar-terrestrial science is pursued by individuals and teams of workers situated in academia, research institutes, industry, and government laboratories. Progress in the field is made in various ways, but publication of results in scientific journals is the principal means of assuring that the knowledge gained from research is available to the public, now and in the future. In general, much of the research in the field is made via careful evaluation of data viewed in the context of fundamental physical principles as set forth in theoretical and analytical models, and computer simulations of physical processes. In addition, there is accumulation of knowledge expressed in the development of empirical or phenomenological models. Experience gained over the past three decades of solar-terrestrial research indicated that advances in the field require a diversity of resources and that the health of the entire discipline depends upon a balance among these. To maintain the health of the discipline, NASA and other federal funding agencies concerned with solar-terrestrial research must work together to insure that the following resources are available in reasonable measure to support solar-terrestrial research endeavors: ground-based facilities; balloons and rockets; spaceborne experiments; information networks; computational resources; models of solar terrestrial processes; data bases and archives; and research students.

1989-09-01

211

Communication architecture of an early warning system  

NASA Astrophysics Data System (ADS)

This article discusses aspects of communication architecture for early warning systems (EWS) in general and gives details of the specific communication architecture of an early warning system against tsunamis. While its sensors are the "eyes and ears" of a warning system and enable the system to sense physical effects, its communication links and terminals are its "nerves and mouth" which transport measurements and estimates within the system and eventually warnings towards the affected population. Designing the communication architecture of an EWS against tsunamis is particularly challenging. Its sensors are typically very heterogeneous and spread several thousand kilometers apart. They are often located in remote areas and belong to different organizations. Similarly, the geographic spread of the potentially affected population is wide. Moreover, a failure to deliver a warning has fatal consequences. Yet, the communication infrastructure is likely to be affected by the disaster itself. Based on an analysis of the criticality, vulnerability and availability of communication means, we describe the design and implementation of a communication system that employs both terrestrial and satellite communication links. We believe that many of the issues we encountered during our work in the GITEWS project (German Indonesian Tsunami Early Warning System, Rudloff et al., 2009) on the design and implementation communication architecture are also relevant for other types of warning systems. With this article, we intend to share our insights and lessons learned.

Angermann, M.; Guenther, M.; Wendlandt, K.

2010-11-01

212

Planetary geology and terrestrial analogs in Asia  

NASA Astrophysics Data System (ADS)

2011 PERC Planetary Geology Field Symposium;Kitakyushu City, Japan, 5-6 November 2011 In spite of the extremely diverse geological settings that exist in Asia, relatively little attention has previously been paid to this region in terms of terrestrial analog studies for planetary application. Asia is emerging as a major center of studies in planetary geology, but no attempt had been made in the past to organize a broadly based meeting that would allow planetary geologists in Asia to meet with ones from more advanced centers, such as the United States and Europe, and that would include the participation of many geologists working primarily on terrestrial research. The Planetary Exploration Research Center (PERC) of the Chiba Institute of Technology hosted the first planetary geology field symposium in Asia to present results from recent planetary geology studies and to exchange ideas regarding terrestrial analogs (http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/index.html).

Komatsu, Goro; Namiki, Noriyuki

2012-04-01

213

POLITICAL COMMUNICATION VERSUS COMMERCIAL COMMUNICATION  

Microsoft Academic Search

The purpose of this paper is to draw a parallel between commercial communication, seen as a basic element of classic marketing and electoral communication, seen as part of political marketing. The processes of policy and message development and dissemination in the political field are, somewhat, akin to market positioning in the commercial sector. For Philip Kotler political marketing is \\

Monica Bija; Máthé Ilona

214

Communication acoustics  

NASA Astrophysics Data System (ADS)

Those aspects of acoustics which concern the relations of acoustics to the information and communication technologies are now frequently called ``communication acoustics.'' After a short review of the history of this field, relevant results from recent research at the Institute of Communication Acoustics at the Ruhr-University of Bochum, Germany, will be reported. This work can be seen in light of the research areas of computational auditory scene analysjs (CASA) and auditory virtual environments (AVE)-both dealing with the parametric representation of auditory scenes. Recent application opportunities and future trends will be discussed. It will be argued that modern communication-acoustical systems-which are often only embedded components in more complex communication systems-require more and more built-in explicit knowledge. Among other things, the development of such components and systems calls for data and knowledge from the cognitive sciences. Today's programs for education in communication engineering and communication acoustics often do not take sufficient account of this trend.

Blauert, Jens

2001-05-01

215

Polio communication.  

PubMed

Substantial investments are being made in the area of communication and social mobilisation to interrupt transmission of wild poliovirus. A number of organisations with active support from the Government of India and various state governments are implementing activities to raise awareness and encourage all families to immunise their children. A mass media campaign is the most recognised health promotion effort on media. Mass media efforts are being backed by intensive social mobilisation and interpersonal communication efforts in polio-endemic states. Advocacy and editorial media environment are key elements of the overall communication approach, creating a conducive environment for the polio programme. PMID:16821663

Galaway, Michael

2005-12-01

216

Study on Satellite Communications using Ultra Wideband (UWB) Signals  

Microsoft Academic Search

In this paper, the possibility of satellite communication systems using a multiband UWB signal format is considered. For terrestrial short-distance high-speed communications, multiband UWB schemes are proposed in IEEE 802.15 TG3a and the discussion is ongoing at the standardization body. In the multiband UWB scheme, frequency hopping is adopted over 3.1 - 10.6 GHz, which is regulated by the FCC

Yoshio KUNISAWA Hiroyasu ISHIKAWA; Hisato IWAI; Hideyuki SHINONAGA

217

Design and analysis of large-scale wireless communications networks  

Microsoft Academic Search

This paper presents fundamental design and performance assessment methodologies for modern large-scale enterprise wireless communications networks comprised of many system components. Large-scale wireless networks are needed to serve mobile users in a region and to satisfy their intra- and inter-region communications requirements by adopting network-on-the-move (NOTM) concepts. For global access, the NOTM systems will connect to wireless and terrestrial networks

Kenneth Y. Jo; Syed R. Ali

2006-01-01

218

A satellite-based climatology (1989-2012) of lake surface water temperature from AVHRR 1-km for Central European water bodies  

NASA Astrophysics Data System (ADS)

The temperature of lakes is an important parameter for lake ecosystems influencing the speed of physio-chemical reactions, the concentration of dissolved gazes (e.g. oxygen), and vertical mixing. Even small temperature changes might have irreversible effects on the lacustrine system due to the high specific heat capacity of water. These effects could alter the quality of lake water depending on parameters like lake size and volume. Numerous studies mention lake water temperature as an indicator of climate change and in the Global Climate Observing System (GCOS) requirements it is listed as an essential climate variable. In contrast to in situ observations, satellite imagery offers the possibility to derive spatial patterns of lake surface water temperature (LSWT) and their variability. Moreover, although for some European lakes long in situ time series are available, the temperatures of many lakes are not measured or only on a non-regular basis making these observations insufficient for climate monitoring. However, only few satellite sensors offer the possibility to analyze time series which cover more than 20 years. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown on the National Oceanic and Atmospheric Administration (NOAA) Polar Operational Environmental Satellites (POES) and on the Meteorological Operational Satellites (MetOp) from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) as a heritage instrument for almost 35 years. It will be carried on for at least ten more years finally offering a unique opportunity for satellite-based climate studies. Herein we present the results from a study initiated by the Swiss GCOS office to generate a satellite-based LSWT climatology for the pre-alpine water bodies in Switzerland. It relies on the extensive AVHRR 1-km data record (1985-2012) of the Remote Sensing Research Group at the University of Bern (RSGB) and has been derived from the AVHRR/2 (NOAA-11, -14) and AVHRR/3 (NOAA-16, -17, -18, -19 and Metop-A). A high accuracy is needed for climate related studies, which requires a careful pre-processing and consideration of the atmospheric state. Especially data from NOAA-16 and prior satellites were prone to unwanted noise, e.g., due to transmission errors or fluctuations in the instrument's thermal state. This has resulted in partly corrupted thermal calibration data and may cause errors of up to several Kelvin in the final brightness temperatures. Therefore, a multistage correction scheme has been applied to the data, in order to minimize these artefacts in the satellite observations. For the LSWT retrieval we have tested three different methods. First, we applied the operational NOAA National Environmental Satellite, Data, and Information Service (NESDIS) and NOAA Pathfinder global sea surface temperature (SST) algorithms to our data set. In addition, we developed an optimized simulation-based scheme making use of the Radiative Transfer for TOVS (RTTOV) Version 10 together with operational analysis and reanalysis data from the European Centre for Medium Range Weather Forecasts (ECMWF). All methods were validated extensively using in situ measurements from lakes with various sizes between 14 km2 (Lake Sempach) and 580 km2 (Lake Geneva). The simulation-based algorithm reduces the RMSE and Bias for the lakes in the study region of Switzerland compared to the global SST algorithms and even small lakes yield good results. Following these successful outcome, the model-based LSWT retrieval shall be expanded to all European lakes covered and recorded by the AVHRR data receiving station at the RSGB.

Riffler, Michael; Wunderle, Stefan

2013-04-01

219

Land mobile communications satellite mission (LAMOCOSAMIS) Task 1: Market study  

NASA Astrophysics Data System (ADS)

Land mobile communication service demand in Europe and the Mediterranean basin in the years 1995-2005 was estimated. A traffic model was derived. There is an exploding demand for land mobile communications in Europe, with overwhelming preference for two way telephone services. The users survey shows a surprising lack of sensitivity to prices and tariffs, which widely contributed to the preeminence of the needs for telephone services. This demand justifies that every effort be made to develop as fast as possible a compatible pan-European terrestrial mobile system. If a large proportion of the needs may be satisfied by terrestrial mobile system solutions, the potential remaining needs for telephony, outside of the presently planned terrestrial mobile, which can be served only by satellite, even under the pessimistic economic scenario and high cost/tariff assumptions, requires a number of equivalent telephone circuits which cannot be achieved with available state of the art technology.

1985-12-01

220

Distributed assimilation of satellite-based snow extent for improving simulated streamflow in mountainous, dense forests: An example over the DMIP2 western basins  

NASA Astrophysics Data System (ADS)

Snow cover area affects snowmelt, soil moisture, evapotranspiration, and ultimately streamflow. For the Distributed Model Intercomparison Project - Phase 2 Western basins, we assimilate satellite-based fractional snow cover area (fSCA) from the Moderate Resolution Imaging Spectroradiometer, or MODIS, into the National Weather Service (NWS) SNOW-17 model. This model is coupled with the NWS Sacramento Heat Transfer (SAC-HT) model inside the National Aeronautics and Space Administration's (NASA) Land Information System. SNOW-17 computes fSCA from snow water equivalent (SWE) values using an areal depletion curve. Using a direct insertion, we assimilate fSCAs in two fully distributed ways: (1) we update the curve by attempting SWE preservation, and (2) we reconstruct SWEs using the curve. The preceding are refinements of an existing simple, conceptually guided NWS algorithm. Satellite fSCA over dense forests inadequately accounts for below-canopy snow, degrading simulated streamflow upon assimilation during snowmelt. Accordingly, we implement a below-canopy allowance during assimilation. This simplistic allowance and direct insertion are found to be inadequate for improving calibrated results, still degrading them as mentioned above. However, for streamflow volume for the uncalibrated runs, we obtain: (1) substantial to major improvements (64-81%) as a percentage of the control run residuals (or distance from observations), and (2) minor improvements (16-22%) as a percentage of observed values. We highlight the need for detailed representations of canopy-snow optical radiative transfer processes in mountainous, dense forest regions if assimilation-based improvements are to be seen in calibrated runs over these areas.

Yatheendradas, Soni; Lidard, Christa D. Peters; Koren, Victor; Cosgrove, Brian A.; de Goncalves, Luis G. G.; Smith, Michael; Geiger, Jim; Cui, Zhengtao; Borak, Jordan; Kumar, Sujay V.; Toll, David L.; Riggs, George; Mizukami, Naoki

2012-09-01

221

Comparison of ground-based and satellite-based NO2 column measurements: First steps to correlating in-situ and remote measurements  

NASA Astrophysics Data System (ADS)

Determining ground-level trace-gas mixing ratios via satellite measurements is limited by the satellite’s spatial resolution (typically on the order of 100 km^2), the relationship between the integrated column of air “seen” by a satellite instrument to a surface concentration, and the overpass schedule. Although satellite-based spectrometers such as Ozone Monitoring Instrument (OMI) aboard Aura are capable of observing regional-to-large urban area pollution events, these measurements are limited temporally by one overpass per day. In support of NASA’s GEO-CAPE mission, the CAPABLE site at NASA Langley Research Center has been established in coordination with the U.S. Environmental Protection Agency and Virginia’s Department of Environmental Quality to provide insight into the relationship between geostationary high temporal resolution measurements from space and continuous in situ surface observations. The focus of this study is to determine the correlation of in situ NO2 measurements with ground-based column NO2 measurements using a direct-sun photometer. Our investigation also incorporates the measurement of boundary-layer parameters (e.g. height, winds) into the interpretation of the analyses. In addition, we present an analysis of how satellite NO2 columns are impacted by pixel size and the distance of the measurement from the LaRC site. From our results, we hope to be able to propose further steps that will lead to better understanding between surface and integrated column measurements so that satellite observations can be better utilized by the air quality user community. Disclaimer: Although this work was reviewed by the U.S. Environmental Protection Agency and National Aeronautics and Space Administration, and approved for publication, it may not necessarily reflect official Agency policy.

Knepp, T.; Pippin, M. R.; Cowen, L.; Martin, R.; Geiger, J.; Murray, J.; Fishman, J.; Neil, D. O.; Scott, C.; Franklin, C.; Kollmeyer, R.; Sorkin, A.; Jennings, T.; Szykman, J.; Quesnel, A.; Sauvage, L.; Yesalusky, M. A.; Smith, W.; Martins, D. K.; Thompson, A. M.; Herman, J. R.; Cede, A.; Abuhassan, N.

2010-12-01

222

Evaluation of ISLSCP Initiative II satellite-based land cover data sets and assessment of progress in land cover data for global modeling  

NASA Astrophysics Data System (ADS)

As an important component of the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II data collection, eight state-of-the-art land cover/use data sets have been compiled and made consistent with the ISLSCP Initiative II land/water mask in support of global modeling efforts. These data sets contain new and improved global data sets at coarse resolutions (1/4, 1/2 and 1°) describing historical, recent and present land cover conditions and are a testament to the tremendous progress made in this area over the past decade. In addition to the historical data, data describing the subcell heterogeneity in land cover are also provided, both in terms of subcell proportions of land cover classes and vegetation continuous fields such as % tree, grass and bare cover. Here we present the various ISLSCPII land cover data sets and compare the principal satellite-derived data sets and the effect of their respective aggregation methods. We find that despite some notable disagreements among similar classes, the satellite-based data sets agree remarkably well over large portions of the Earth's surface (over 50% for all resolutions). We also find that the methods of aggregation, whether done by a strictly dominant type, or using more information on subcell tree cover, can have an important impact on the final output and need to be considered by the user. Finally, by integrating the vegetation continuous fields data into our analyses we are able to show that the principal differences in terms of discrete land cover classes are in fact transition zones between similar classes.

Brown de Colstoun, Eric C.; Defries, Ruth S.; Townshend, John R. G.

2006-11-01

223

Communicating biosecurity.  

PubMed

Shifting from risk-calculation orientations focusing on populations to preparedness perspectives that model uncertainty through scenario-based projections, biosecurity debates redefined notions of "health" and "security." Nevertheless, a key focus of biosecurity discussions--the domain labeled "communication"--has not been fundamentally rethought, even as it has expanded and professionalized. Bracketing preconceived ideas about the term's content, the article traces debates about biosecurity "communication" from the 1990s to the present, drawing on ethnography and textual analysis. Using a notion of biocommunicability, the cultural modeling of how discourse is produced, circulates, and is received, the article analyzes assumptions regarding subjects, subject-positions, objects, spatializing and temporalizing practices, scales, economies of affect, and regimes of ethics that are built into discourse about "communication." Ironically, the conviction that "communication" is of marginal importance as a focus of critical inquiry, seemingly shared by most medical anthropologists, enables these assumptions to fundamentally shape discussions of biosecurity and emergency management. PMID:21218354

Briggs, Charles L

2011-01-01

224

Communication Planning.  

National Technical Information Service (NTIS)

Communication planning in developing countries is discussed in individual articles on theory, knowledge production and utilization, planning at the regional level, software, and rural development. A nutrition education project and three experiments in dev...

1978-01-01

225

Acoustic Communication  

NSDL National Science Digital Library

Concise lecture on sound production in insects. Stridulation, forced air through spiracles, wing vibration, and tapping are all discussed with examples. Advantages and disadvantages of sound production are also discussed. The page also links to chemical, and visual communication pages.

0002-11-30

226

Quantum Communication  

NASA Astrophysics Data System (ADS)

Few would dispute that the science of particle physics in the United States has reached a crossroads. Policies, decisions, and events of the coming decade will be critical in determining whether the United States continues to carry out a competitive program of leadership in this field of fundamental science. The field of particle physics has responded to this reality by fundamentally changing its model of communication from “business as usual” to a strategic and collaborative method that is clearly focused on achieving a healthy future for the science. Over the past half-dozen years, the particle physics community has gone from being an oft-cited example of how not to communicate effectively, to a frequently cited—and emulated—model for science communication. This review outlines the new approach toward communication in particle physics and then goes into detail about three case studies.

Jackson, Judy; Calder, Neil

2007-11-01

227

Communication Scheduling.  

National Technical Information Service (NTIS)

The high arithmetic rates of media processing applications require architectures with tens to hundreds of functional units, multiple register files, and explicit interconnect between functional units and register files. Communication scheduling enables sc...

P. Mattson W. J. Dally S. Rixner U. J. Kapasi J. D. Owens

2000-01-01

228

Wireless Communication  

NSDL National Science Digital Library

This quicktime animation examines the basics in wireless communication. Wireless communication has become pervasive in everyday life, providing convenience, piece of mind as well as emergency preparedness for its users through instant accessibility. The cell phone antenna is the link to the outside world. Designed to transmit as well as receive the RF signals, it efficiently couples the electromagnetic waves to the transmitter and receiver.

Van Zeghbroeck, Bart J.

2012-08-08

229

Communicating Biosecurity  

Microsoft Academic Search

Shifting from risk-calculation orientations focusing on populations to preparedness perspectives that model uncertainty through scenario-based projections, biosecurity debates redefined notions of “health” and “security.” Nevertheless, a key focus of biosecurity discussions—the domain labeled “communication”—has not been fundamentally rethought, even as it has expanded and professionalized. Bracketing preconceived ideas about the term's content, the article traces debates about biosecurity “communication” from

Charles L. Briggs

2011-01-01

230

Police Communications  

NASA Astrophysics Data System (ADS)

Oklahoma City Police Department developed a computerized communications system, based on Johnson Space Center's (JSC's) 1960-mission control knowledge. JSC furnished information on lighting and other fatigue reducing measures, and provided specifications for equipment and design layouts. JSC also advised OCPD how to avoid communications bottlenecks associated with simultaneous handling of telephone, radio and inner-office transmissions. Oklahoma City saved money in reduced design and engineering costs by utilizing the already developed NASA technology.

1981-01-01

231

Communicating Astronomy  

NASA Astrophysics Data System (ADS)

Science Communication plays a crucial role in education and in the public understanding of science. It shortens the distance between scientific research, the school and the general public. Astronomy has a privileged position in the process of science communication since it embraces different areas of knowledge such as mathematics, physics, chemistry, geology and biology. It is capable of attracting a vast audience and is a powerful tool for science popularization. Nowadays, science must compete with many other subjects for a place in the media and in the public's attention. This paradigm has raised the standards and demands for science communication and pushed it into professionalism. The International Year of Astronomy 2009 (IYA2009) is one of the biggest challenges for astronomy communication. There are two key elements in the communication strategy that are often forgotten: detailed description of objectives and goals and evaluation of the results. They are in opposite poles of the communication strategy, but must both be taken into account from the beginning of any activity. In this paper we will present some guidelines that can be helpful in the initial planning of outreach activities, as well as the evaluation of its results.

Russo, P.; Barrosa, Mariana

2007-08-01

232

Outlooks for GaAs terrestrial photovoltaics  

Microsoft Academic Search

An overview of the use of GaAs photovoltaic devices as an alternative to Si devices for large scale terrestrial power generation is presented. A review of the structure and the operational advantages and limitations of p-n homojunction, heterostructure, semitransparent Schottky barrier, and drift field types of photovoltaic devices is given. Operational parameters, technology, materials economy, capacity, and cost performance of

J. M. Woodall; H. J. Hovel

1975-01-01

233

Terrestrial analogs of possible Martian habitats  

Microsoft Academic Search

Four environmental factors are responsible for the apparent absence of life on or near the surface of Mars: radiation, reactive oxidants, aridity and low temperature. The three latter factors are also present in terrestrial environments that approximate, although do not reach, the intensity of Martian conditions. Nor do they occur together in the same environments, yet they allow studying the

E. I. Friedmann

2006-01-01

234

Effects of acid precipiitation on terrestrial ecosystems  

Microsoft Academic Search

This volume contains papers presented at a NATO Advanced Research Institute, sponsored by their Eco-Sciences Panel, on the Effects of Acid Precipitation on Vegetation and Soils, held May 22-26, 1978, at Toronto. The Advanced Research Institute was held specifically to bring together international experts to present, examine and debate the scientific research relevant to such terrestrial ecosystems. The identification of

T. C. Hutchinson; M. Havas

1980-01-01

235

MICROBIAL ECOLOGY OF THE TERRESTRIAL SUBSURFACE  

EPA Science Inventory

A current view is presented of the microbial ecology of the terrestrial subsurface by considering primarily the ecology of shallow aquifer sediments. The properties of the aquifer sediments and groundwater determine their ability to support microbial life and control the abundanc...

236

Terrestrial and space techniques in earthquake research  

Microsoft Academic Search

A report is given on an international workshop which was held to discuss recent advances in experimental techniques for the monitoring of crustal dynamics in earthquake zones. Experts from countries throughout the world, who are concerned with earthquakes and earthquakes disaster prevention, participated and discussed various terrestrial as well as space techniques presently applied or most likely to become applicable

A. Vogel

1979-01-01

237

Terrestrial Planet Finder: technology development plans  

Microsoft Academic Search

One of humanity's oldest questions is whether life exists elsewhere in the universe. The Terrestrial Planet Finder (TPF) mission will survey stars in our stellar neighborhood to search for planets and perform spectroscopic measurements to identify potential biomarkers in their atmospheres. In response to the recently published President's Plan for Space Exploration, TPF has plans to launch a visible-light coronagraph

Christian A. Lindensmith

2004-01-01

238

Terrestrial Planet Finder: Technology Development Plans  

Microsoft Academic Search

One of humanity's oldest questions is whether life exists elsewhere in the universe. The Terrestrial Planet Finder (TPF) mission will survey stars in our stellar neighborhood to search for planets and perform spectroscopic measurements to identify potential biomarkers in their atmospheres. In response to the recently published President's Plan for Space Exploration, TPF has plans to launch a visible-light coronagraph

Chris Lindensmith

239

Terrestrial plant biopolymers in marine sediments  

Microsoft Academic Search

The vascular land plant biopolymers lignin and cutin were surveyed in the surface sediments of coastal and open ocean waters by controlled alkaline CuO oxidation\\/reaction. Two contrasting oceanic regimes were studied: the northwest Mediterranean (NWM) Sea, which receives significant particulate terrigenous debris through riverine discharge; and the northeast Atlantic (NEA) Ocean, with poorly characterised terrestrial carbon inputs. In the NWM

Mark A. Gough; R. Fauzi; C. Mantoura; Martin Preston

1993-01-01

240

Monogenetic volcanoes of the terrestrial planets  

Microsoft Academic Search

Monogenetic volcanic activity has produced cinder cones and small shield volcanoes on the earth, moon, and Mars. Extraterrestrial cinder cones have median volumes only 25% as large as average terrestrial cinder cones, implying that their magma chambers are smaller and shallower (1 km depth vs 3 km). Ejection velocities for lunar and Martian cinder cones range from 20 to 70

C. A. Wood

1979-01-01

241

Calibration of Solar Cells in Terrestrial Sunlight.  

National Technical Information Service (NTIS)

A method of calibrating solar cells in sunlight is described. This method has been used for at least 15 years, and produces a value of the solar cell's short circuit current for any predetermined space of terrestrial condition. The main advantage of this ...

M. A. H. Davies C. Goodbody

1991-01-01

242

Subsolidus convective cooling histories of terrestrial planets  

Microsoft Academic Search

The subsolidus convective cooling histories of terrestrial planets evolving from hot initial states are investigated quantitatively. A simple analytic model simulating average heat flux from a vigorously convecting mantle and incorporating a mantle viscosity proportional to mantle temperature and a lithosphere which thickens as the planet cools is employed. Heat flux from the convecting mantle is calculated on the basis

G. Schubert; P. Cassen; R. E. Young

1979-01-01

243

Geomorphological processes on terrestrial planetary surfaces  

Microsoft Academic Search

The impact of photographic explorations of the moon, Mars, and Mercury on studies of terrestrial surface processes is studied, with attention given to volcanic features, eolian erosion, ground ice and permafrost, and sapping as a geomorphological process. Finally, the ongoing deformation of the earth's crust is considered with reference to seismic activity and micromorphology, seismic activity recorded by microstratigraphy, microchronology,

R. P. Sharp

1980-01-01

244

Transposer systems for digital terrestrial television  

Microsoft Academic Search

The UK digital terrestrial television (DTT) network has completed its first phase of roll-out, with over 70% of the population now able to receive all six digital multiplexes. Whilst this is an impressive achievement, the current analogue TV network can cover 99.7% of the UK population and digital satellite systems can boast virtually 100% coverage, so DTT still has some

Peter B. Kenington; Keith Hayler; Peter Moss; David J. Edwards; Alan P. Jenkins; Mark Johnstone

2001-01-01

245

Terrestrial analog studies for Martian patterned ground  

Microsoft Academic Search

A recurring problem in understanding Martian patterned ground is explaining its large size. Terrestrial patterned ground in Swedish Lapland offers an analog that may help explain this. In cold, arid regions with strong winds, polygonal features are accentuated paralled to the dominant wind direction. Preliminary results of a comparison between Martian polygonal troughs and dominant wind directions suggests a good

L. A. Rossbacher

1985-01-01

246

Dinosaurs and the Cretaceous Terrestrial Revolution  

Microsoft Academic Search

The observed diversity of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50 Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has long been debated whether dinosaurs were part of the Cretaceous Terrestrial Revolution (KTR), from 125-80 Myr ago, when flowering plants, herbivorous and

Graeme T. Lloyd; Katie E. Davis; Davide Pisani; James E. Tarver; Marcello Ruta; Manabu Sakamoto; David W. E. Hone; Rachel Jennings; Michael J. Benton

2008-01-01

247

The Carbon Cycles of Chinese Terrestrial Ecosystems  

Microsoft Academic Search

The changes of Chinese terrestrial carbon storage depend not only on biogeochemical and climatological processes, but also on human activities and their interaction with carbon cycle. China,covering about 133.7 million hectares of forested land, has climate regimes ranging from tropical, to subtropical, temperate and cold temperate zones, and from southeast to northwest humid, semi arid and arid zones. A long

C. Peng; J. Fang; Z. Guo; H. Wu

2002-01-01

248

Snowmelt monitoring with Terrestrial Laser Scanner Measurements  

Microsoft Academic Search

The increasing use of satellite data has caused an increasing need for validation data. Terrestrial laser scanning (TLS) and Mobile Mapping Systems (MMS) are potential methods of gaining information on vast areas at remote locations. We have investigated the snowmelt 2009 using stationary and mobile TLS during the SNORTEX -campaign (Snow Reflectance Transition Experiment) in several locations in Finnish Lapland

Kati Anttila; Sanna Kaasalainen; Harri Kaartinen; Anssi Krooks; Terhikki Manninen; Panu Lahtinen; Aku Riihelä; Niilo Siljamo; Laura Thölix; Tuure Karjalainen

2010-01-01

249

Early Terrestrial Arthropods: A Fragmentary Record  

Microsoft Academic Search

The earliest unequivocal terrestrial fossils are uppermost Silurian (Pridoli) myriapods, presumed to be pioneer decomposers. Descendants of their marine ancestors may be discernible in the Cambrian lobopod Aysheaia (recently challenged). Known euthycarcinoids are too late except as survivors from such a lobopod ancestry. Unique arthropods are also known from Cambrian and Ordovician lake deposits, but shed no light on origin

W. D. I. Rolfe

1985-01-01

250

Terrestrial Planets: Volatiles Loss & Speed of Rotation  

Microsoft Academic Search

There is a close relation between orbiting frequencies of terrestrial planets and intensities of their outgassing [1]. ``Sweeping'' out volatiles of their bodies is provoked and facilitated by body shaking (wave oscillations) caused by movement of celestial bodies in elliptical orbits. Non-round orbits cause inertia-gravity warpings in all spheres of the bodies producing their tectonic granulation. The higher orbiting frequency

G. G. Kochemasov

2004-01-01

251

SETI [Search for ExtraTerrestrial Intelligence  

Microsoft Academic Search

Some critics of the Search for Extra-Terrestrial Intelligence (SETI) like to bolster their arguments with what they call the Fermi Paradox. Legend has it that one day at Los Alamos, shortly after the Alamogordo test (when the first atomic bomb was exploded in the desert about 50 miles northwest of this town on July 16, 1945), Enrico Fermi abruptly broke

B. M. Oliver

1994-01-01

252

CHANGE DETECTION VIA TERRESTRIAL LASER SCANNING  

Microsoft Academic Search

We present in this paper an algorithm for the detection of changes based on terrestrial laser scanning data. Detection of changes has been a subject for research for many years, seeing applications such as motion tracking, inventory-like comparison and deformation analysis as only a few examples. One of the more difficult tasks in the detection of changes is performing informed

Reem Zeibak; Sagi Filin

2007-01-01

253

Plate tectonics on the terrestrial planets  

Microsoft Academic Search

Plate tectonics is largely controlled by the buoyancy distribution in oceanic lithosphere, which correlates well with the lithospheric age. Buoyancy also depends on compositional layering resulting from pressure release partial melting under mid-ocean ridges, and this process is sensitive to pressure and temperature conditions which vary strongly between the terrestrial planets and also during the secular cooling histories of the

P van Thienen; N. J Vlaar; A. P van den Berg

2004-01-01

254

First RHESSI terrestrial gamma ray flash catalog  

Microsoft Academic Search

We present a summary of data from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) terrestrial gamma ray flash (TGF) catalog. We describe the RHESSI search algorithm and discuss its limitations due to its design emphasis on cleanliness rather than completeness. This search algorithm has identified 820 TGFs between March of 2002 and February of 2008. Radiation damage to

B. W. Grefenstette; D. M. Smith; B. J. Hazelton; L. I. Lopez

2009-01-01

255

76 FR 50274 - Terrestrial Environmental Studies for Nuclear Power Stations  

Federal Register 2010, 2011, 2012, 2013

...Terrestrial Environmental Studies for Nuclear Power Stations AGENCY: Nuclear Regulatory...Terrestrial Environmental Studies for Nuclear Power Stations.'' This guide provides...supporting licensing decisions for nuclear power reactors. DATES: Submit...

2011-08-12

256

77 FR 18271 - Terrestrial Environmental Studies for Nuclear Power Stations  

Federal Register 2010, 2011, 2012, 2013

...Terrestrial Environmental Studies for Nuclear Power Stations AGENCY: Nuclear Regulatory...Terrestrial Environmental Studies for Nuclear Power Stations.'' This guide provides...supporting licensing decisions for nuclear power reactors. ADDRESSES:...

2012-03-27

257

Terrestrial Television Broadcasting in China: Technologies and Applications  

Microsoft Academic Search

\\u000a This chapter will discuss the two main terrestrial television broadcasting systems widely used in China. One is the China\\u000a Terrestrial Television Broadcasting (CTTB) standard which is named as “Frame structure, channel coding and modulation for\\u000a digital television terrestrial broadcasting system”. It was issued in August 2006 as a mandatory standard for traditional\\u000a terrestrial broadcasting and had been put into execution

Wenjun Zhang; Yunfeng Guan; Xiaokang Yang; Weiqiang Liang

2010-01-01

258

Low-Altitude Remote Sensing with Unmanned Radio-Controlled Helicopter Platforms: A Potential Substitution to Satellite-based Systems for Precision Agriculture Adoption under Farming Conditions in Developing Countries  

Microsoft Academic Search

In developing countries with small and medium farm holdings, satellite-based remote sensing is found unsuitable for precision agriculture technology adoption, due to low spatial and high temporal resolution of imagery. Image acquisition system mounted on unmanned helicopter platforms can provide user-specified and near-real time images for quick assessment of the crop and soil status giving enough time for preventive measures.

Kishore C. Swain; H. P. W. Jayasuriya; V. M. Salokhe

259

Linking Terrestrial and Marine Conservation Planning and Threats Analysis  

Microsoft Academic Search

The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system

HEATHER TALLIS; ZACH FERDAÑA; ELIZABETH GRAY

2008-01-01

260

Research of remote control for Chinese Antarctica Telescope based on iridium satellite communication  

NASA Astrophysics Data System (ADS)

Astronomers are ever dreaming of sites with best seeing on the Earth surface for celestial observation, and the Antarctica is one of a few such sites only left owing to the global air pollution. However, Antarctica region is largely unaccessible for human being due to lacking of fundamental living conditions, travel facilities and effective ways of communication. Worst of all, the popular internet source as a general way of communication scarcely exists there. Facing such a dilemma and as a solution remote control and data transmission for telescopes through iridium satellite communication has been put forward for the Chinese network Antarctic Schmidt Telescopes 3 (AST3), which is currently under all round research and development. This paper presents iridium satellite-based remote control application adapted to telescope control. The pioneer work in China involves hardware and software configuration utilizing techniques for reliable and secure communication, which is outlined in the paper too.

Xu, Lingzhe; Yang, Shihai

2010-07-01

261

Communicating Science  

NASA Astrophysics Data System (ADS)

We are in an era of rapidly changing communication media, which is driving a major evolution in the modes of communicating science. In the past, a mainstay of scientific communication in popular media was through science “translators”; science journalists and presenters. These have now nearly disappeared and are being replaced by widespread dissemination through, e.g., the internet, blogs, YouTube and journalists who often have little scientific background and sharp deadlines. Thus, scientists are required to assume increasing responsibility for translating their scientific findings and calibrating their communications to non-technical audiences, a task for which they are often ill prepared, especially when it comes to controversial societal issues such as tobacco, evolution, and most recently climate change (Oreskes and Conway 2010). Such issues have been politicized and hi-jacked by ideological belief systems to such an extent that constructive dialogue is often impossible. Many scientists are excellent communicators, to their peers. But this requires careful attention to detail and logical explanation, open acknowledgement of uncertainties, and dispassionate delivery. These qualities become liabilities when communicating to a non-scientific audience where entertainment, attention grabbing, 15 second sound bites, and self assuredness reign (e.g. Olson 2009). Here we report on a program initiated by NCAR and UCAR to develop new approaches to science communication and to equip present and future scientists with the requisite skills. If we start from a sound scientific finding with general scientific consensus, such as the warming of the planet by greenhouse gases, then the primary emphasis moves from the “science” to the “art” of communication. The art cannot have free reign, however, as there remains a strong requirement for objectivity, honesty, consistency, and above all a resistance to advocating particular policy positions. Targeting audience attitudes and beliefs, which studies such as the Six Americas research help identify, is key to effective science communications (e.g. Leiserowitz, Maibach, et al, 2009). We argue that the impact of the scientific message can be substantially improved by targeting it to these additional factors. This does require an understanding of the audience and a repackaging of the message to different societal groups. Logical and dispassionate presentation of evidence works for a target scientific audience, but major decisions from the policy to the personal level are influenced by many factors including immediacy, economics, culture, community leaders, emotional framing, and ideological filters.

Holland, G. J.; McCaffrey, M. S.; Kiehl, J. T.; Schmidt, C.

2010-12-01

262

Assessing the impact of end-member selection on the accuracy of satellite-based spatial variability models for actual evapotranspiration estimation  

NASA Astrophysics Data System (ADS)

This study examines the impact of end-member (i.e., hot and cold extremes) selection on the performance and mechanisms of error propagation in satellite-based spatial variability models for estimating actual evapotranspiration, using the triangle, surface energy balance algorithm for land (SEBAL), and mapping evapotranspiration with high resolution and internalized calibration (METRIC) models. These models were applied to the soil moisture-atmosphere coupling experiment site in central Iowa on two Landsat Thematic Mapper/Enhanced Thematic Mapper Plus acquisition dates in 2002. Evaporative fraction (EF, defined as the ratio of latent heat flux to availability energy) estimates from the three models at field and watershed scales were examined using varying end-members. Results show that the end-members fundamentally determine the magnitudes of EF retrievals at both field and watershed scales. The hot and cold extremes exercise a similar impact on the discrepancy between the EF estimates and the ground-based measurements, i.e., given a hot (cold) extreme, the EF estimates tend to increase with increasing temperature of cold (hot) extreme, and decrease with decreasing temperature of cold (hot) extreme. The coefficient of determination between the EF estimates and the ground-based measurements depends principally on the capability of remotely sensed surface temperature (Ts) to capture EF (i.e., depending on the correlation between Ts and EF measurements), being slightly influenced by the end-members. Varying the end-members does not substantially affect the standard deviation and skewness of the EF frequency distributions from the same model at the watershed scale. However, different models generate markedly different EF frequency distributions due to differing model physics, especially the limiting edges of EF defined in the remotely sensed vegetation fraction (fc) and Ts space. In general, the end-members cannot be properly determined because (1) they do not necessarily exist within a scene, varying with the spatial extent, resolution, and quality of satellite images being used and/or (2) different operators can select different end-members. Furthermore, the limiting edge of EF = 0 in the fc-Ts space varies with the model, with SEBAL-type models having inherently an increasing curvilinear limiting edge of EF = 0 with fc. The spatial variability models therefore require careful calibration in order to deduce reasonable EF-limiting edges and then confine the magnitudes of EF estimates.

Long, Di; Singh, Vijay P.

2013-05-01

263

A satellite based algorithm for identifying dust episodes: the regime of episodes in the Mediterranean basin and evaluation against surface measurements  

NASA Astrophysics Data System (ADS)

An objective and dynamic algorithm was set up, using daily data of various aerosol optical properties from different satellite databases, which identifies the desert dust (DD) episodes and classifies them into strong and extreme ones. The algorithm is applied to derive the regime of DD episodes over the broader Mediterranean basin over the period 2000-2007. First, the algorithm was tested through comparisons against surface based particulate matter (PM) and AERONET measurements from stations distributed across the Mediterranean basin. The comparisons have shown a reasonable ability of the algorithm to detect the DD episodes occurring within the study region, with largest disagreements with PM data in summer, when African dust transport has a great vertical extent restricting the ability of PM measurements to capture them. The DD episodes in the Mediterranean basin are quite frequent (up to 11.4 episodes/year) having a significant spatial and temporal variability in their frequency of occurrence and intensity. Thus, strong DD episodes occur more frequently in the western Mediterranean basin while extreme ones appear more frequently over the central Mediterranean Sea. In addition, there is a predominant latitudinal variability in both frequency and intensity of DD episodes, both being decreased from south to north. A significant seasonal variation of the frequency of DD episodes was also found. More specifically, both strong and extreme episodes are more frequent during summer in the western Mediterranean basin and during spring in its central and eastern parts. In more than 85% of cases, Mediterranean episodes last a bit more than one day on average, but their duration can be as long as 6 days for strong episodes and 4 days for extreme ones. A noticeable year by year variability of DD episodes has been also found, especially concerning their frequency. The spatial and temporal patterns of Mediterranean DD episodes can be explained by the regional surface pressure and precipitation spatio-temporal patterns, as well as by the variability of North Atlantic Oscillation (NAO). Thus, our results indicate a decreasing frequency of Mediterranean DD episodes over the period 2000-2007, especially over land surfaces, in line with decreasing NAO Index over the same period. The present satellite based tool for identifying DD episodes is useful because it enables a complete spatial coverage, which is necessary for better understanding the larger scale processes that determine the regime of DD episodes in the Mediterranean, and it is planned to be used to other key dust regions of the globe.

Gkikas, Antonis; Hatzianastassiou, Nikos; Mihalopoulos, Nikos; Katsoulis, Vasilis; Kazadzis, Stelios; Pey, Jorge; Querol, Xavier; Torres, Omar

2013-04-01

264

Evaluation of snow models in terrestrial biosphere models using ground observation and satellite data: impact on terrestrial ecosystem processes  

Microsoft Academic Search

Snow is important for water management, and an important component of the terrestrial biosphere and climate system. In this study, the snow models included in the Biome-BGC and Terrestrial Observation and Prediction System (TOPS) terrestrial biosphere models are compared against ground and satellite observations over the Columbia River Basin in the US and Canada and the impacts of differences in

Kazuhito Ichii; Michael A. White; Petr Votava; Andrew Michaelis; Ramakrishna R. Nemani

2007-01-01

265

Space and Terrestrial Photovoltaics: Synergy and Diversity  

NASA Astrophysics Data System (ADS)

A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the '70s and '80s and the '90s and beyond. The synergy of both communities in the beginning and once again in the present and hopefully future are highlighted, with examples of the important features in each program. The space community which was impressed by the light-weight and reliability of photovoltaics drove much of the early development. Even up to today, nearly every satellites and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems were only a small fraction of the satellite and launch cost, the use of much of this technology for the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advancements, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost non-existent. Recent work by both communities have focused on the development thin film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in III-V materials and thin film materials. Basic photovoltaics research including these current trends in nanotechnology provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars.

Bailey, Sheila; Raffaelle, Ryne; Emery, Keith

2002-10-01

266

Comparison of Satellite based measurements of the Tropospheric HDO/H2O ratio from TES with in situ measurements at Mauna Loa Observatory  

NASA Astrophysics Data System (ADS)

New Global satellite observations of water vapor and its isotopes from TES, IASI, and SCIAMACHY add a new constraint for estimating evaporation and precipitation rates and partitioning ocean versus terrestrial moisture sources. Here we show the results of a validation campaign between measurement of the HDO/H2O ratio from the Tropospheric Emission Spectrometer and in situ measurements taken at the NOAA Mauna Loa observatory using loaned instruments from Picarro and Los Gatos Research and JPL (Lance Christensen PI). For these data we find that the TES measurements of the HDO/H2O ratio are sensitive to boundary layer and lower tropospheric concentrations. After accounting for the TES a priori bias and vertical sensitivity we find that the TES measurements agree with the in situ data to within 10 parts thousand relative to SMOW, in agreement with the expected TES random errors.

Worden, J.; Noone, D. C.; Brown, D. P.; Lee, J.; Bowman, K. W.; Galewsky, J.

2009-12-01

267

Communications Network  

NASA Astrophysics Data System (ADS)

The Multi-Compatible Network Interface Unit (MCNIU) is intended to connect the space station's communications and tracking, guidance and navigation, life support, electric power, payload data, hand controls, display consoles and other systems, and also communicate with diverse processors. Honeywell is now marketing MCNIU commercially. It has applicability in certain military operations or civil control centers. It has nongovernment utility among large companies, universities and research organizations that transfer large amounts of data among workstations and computers. *This product is no longer commercially available.

1990-01-01

268

Crisis Communication: The Business Communicator's Strategies for Communicating under Stress.  

ERIC Educational Resources Information Center

|Uses the 1979 Three Mile Island nuclear plant accident to illustrate the communication problems embedded in a crisis. Describes the reactions created by the stress related to crisis. Suggests business communication strategies for improving communication to the public. (SR)|

Vielhaber, Mary E.

1990-01-01

269

Conformance testing to space communication network  

NASA Astrophysics Data System (ADS)

Space Internet technology is the Internet that refers to technology which is widely used in the terrestrial network, improved under the space communications feature, thus using the improved Internet protocols and technology, to meet the needs of future space mission technology. In protocol engineering area, conformance testing is a very important step. The purpose of conformance testing is to determine to what extent a single implementation of a particular standard conforms to the individual requirements of that standard. Conformance testing can increase the confidence level of implementation complying with the protocol specification, and enhance the probability of interoperability between different implementation. The ISO/IEC9646 standard described by ISO is the maturest theory in protocol conformance testing theories. Space communication network test framework is proposed, in which the test architecture is defined for conformance testing to space communication network. In this paper, the ISO9646 standard is improved, in order to meet the requirements of conformance testing of space communication network. The contribution of this paper is the proposition of a complete method to the design of conformance testing against space communication network. The simulation results have shown that the method has better test results, to meet the space communications network testing needs. With the testing of the space communications network protocol implementation, we discovered the problems of the protocol implementation. It has verified the theory and method.

Xie, Lei; Wei, Jiaolong; Zhu, Guangxi

2007-11-01

270

Solar-Terrestrial Data Integration using Ontologies  

NASA Astrophysics Data System (ADS)

Data-integration across a number of disciplines is a key requirement to be facilitated by virtual observatories and in particular the Virtual Solar-Terrestrial Observatory(VSTO). Our experience to date indicates that semantic interoperability is a viable and robust approach. We have encodings for the VSTO ontology in OWL - the Web Ontology Language - using both open-source and commercial tools and have implemented a number of use-cases. We aim to demonstrate data-integration between solar atmospheric data (e.g. coronal mass ejections), and the resulting impacts on the terrestrial ionosphere (e.g.aurora). In this presentation, we outline the methodologies, the developed use-cases, ontologies and their current implementation.

Cinquini, L.; McGuinness, D.; Fox, P.; Benedict, J.; Darnell, T.; Middleton, D.; Garcia, J.; West, P.

2006-05-01

271

Method for identifying anomalous terrestrial heat flows  

DOEpatents

A method for locating and mapping the magnitude and extent of terrestrial heat-flow anomalies from 5 to 50 times average with a tenfold improved sensitivity over orthodox applications of aerial temperature-sensing surveys as used for geothermal reconnaissance. The method remotely senses surface temperature anomalies such as occur from geothermal resources or oxidizing ore bodies by: measuring the spectral, spatial, statistical, thermal, and temporal features characterizing infrared radiation emitted by natural terrestrial surfaces; deriving from these measurements the true surface temperature with uncertainties as small as 0.05 to 0.5 K; removing effects related to natural temperature variations of topographic, hydrologic, or meteoric origin, the surface composition, detector noise, and atmospheric conditions; factoring out the ambient normal-surface temperature for non-thermally enhanced areas surveyed under otherwise identical environmental conditions; distinguishing significant residual temperature enhancements characteristic of anomalous heat flows and mapping the extent and magnitude of anomalous heat flows where they occur.

Del Grande, Nancy Kerr (San Leandro, CA)

1977-01-25

272

Terrestrial Laser Scanner for Scour Visualizaton  

NASA Astrophysics Data System (ADS)

Examination of spatio-temporal variations of a terrestrial surface requires high-resolution measurements. Surface Examining Imager (SExI) developed by the University of Iowa Lidar Group is a terrestrial laser measurement system capable of spatially profiling a relatively small area (<20m^2) with mm-scale resolution. It was designed to be simple, affordable, and robust. Because the system employs line of sight principles, two SExIs can be deployed to scan the same area from different positions to see behind surface features and increase spatial resolution. Snell's law of refraction has been applied to underwater datasets to obtain a bathymetric survey for use in sediment scour visualization. This technique has been paired with Particle Image Velocimetry (PIV) to overlay surface velocity profiles on a raster image of the bathymetry.

Plenner, S.; Eichinger, W. E.

2011-12-01

273

Intermittent plasma fluctuation in the terrestrial foreshock  

NASA Astrophysics Data System (ADS)

In the paper the intermittent plasma fluctuation in the terrestrial foreshock is studied, using the FGM magnetic records of the Cluster mission. It is argued that the intermittent state of the plasma regime can be adequately measured in certain space and time through the fourth statistical moments, i.e. the flatness of the incremental magnetic records. It is emphasized that using the simultaneous multi-spacecraft observations, the intermittency can be revealed not only in temporal, but also in spatial scale. By computing the flatness along the orbit of the Cluster mission we present the spatial variation of the intermittent state of the foreshock plasma in terms of the distance from the terrestrial bow shock (BS) and the angle of incidence of the IMF line to the BS normal. The relation between the level of intermittent plasma state and the varying solar wind parameters (bulk speed, Alfvén Mach number, dynamic pressure) is also studied.

Kovács, P.; Vadász, G.; Heilig, B.

2012-04-01

274

Evolution of Herbivory in Terrestrial Vertebrates  

NASA Astrophysics Data System (ADS)

Although herbivory probably first appeared over 300 million years ago, it only became established as a common feeding strategy during Late Permian times. Subsequently, herbivory evolved in numerous lineages of terrestrial vertebrates, and the acquisition of this mode of feeding was frequently associated with considerable evolutionary diversification in those lineages. This book represents a comprehensive overview of the evolution of herbivory in land-dwelling amniote tetrapods in recent years. In Evolution of Herbivory in Terrestrial Vertebrates, leading experts review the evolutionary history and structural adaptations required for feeding on plants in the major groups of land-dwelling vertebrates, especially dinosaurs and ungulate mammals. As such, this volume will be the definitive reference source on this topic for evolutionary biologists and vertebrate paleontologists.

Sues, Hans-Dieter

2000-08-01

275

The precambrian evolution of terrestrial life.  

NASA Astrophysics Data System (ADS)

The early appearance of life on Earth suggests that under appropriate environmental conditions the probability of chemical evolution proceeding to the point of biogenesis may be reasonably high. Most of biological history has been the history of microorganisms, with tissue-grade plants and animals characterizing only the most recent 15% or so of the fossil record. Intelligent life has occupied only the latest instant in geological time. The time table of terrestrial evolution is governed more by the particulars of our planet's physical and biological history than by some universal tempo of evolutionary change. One aspect of terrestrial life that is likely to be universal is the organization of populations into efficient biogeochemical systems.

Knoll, A. H.

276

The search for extra-terrestrial intelligence.  

PubMed

Modern history of the search for extra-terrestrial intelligence is reviewed. The history of radio searches is discussed, as well as the major advances that have occurred in radio searches and prospects for new instruments and search strategies. Recent recognition that searches for optical and infrared signals make sense, and the reasons for this are described, as well as the equipment and special detection methods used in optical searches. The long-range future of the search for extra-terrestrial intelligence (SETI) is discussed in the context of the history of rapid change, on the cosmic and even the human time scale, of the paradigms guiding SETI searches. This suggests that SETI searches be conducted with a very open mind. PMID:21220287

Drake, Frank

2011-02-13

277

Water wave communication in the genus Bombina (amphibia).  

PubMed

Amphibians were phylogenetically the first vertebrates to leave the aquatic environment and cope with terrestrial conditions including effects of gravity and substrate on movement and communication. Studies of extant primitive amphibians, which have conserved ancestral morphology and behavior, may help us to understand how gravitational adaptation from aquatic to terrestrial environments occurred. The anuran genus Bombina is a candidate for this type of investigation. In particular, a member of this genus, B. orientalis, is known for its low reaction threshold to minor changes of angular acceleration. We hypothesize that a heightened sensitivity to angular and mechanical accelerations evolved with wave communication. Comparisons of such behavior among B. variegata, B. bombina and B. orientalis may shed light on the evolution of reproductive systems based on water wave communication and relevant vestibular sensitivity. This may represent a transition to derived vocalization modes, which is seen in B. bombina to a certain degree. PMID:11803958

Seidel, B; Yamashita, M; Choi, I H; Dittami, J

2001-01-01

278

Communications Electronics.  

ERIC Educational Resources Information Center

|This module is the third in a series of electronics publications and serves as a supplement to "General Electronics Technician." It is designed to provide students with an overview of the broad field of communications. Included are those tasks above the basic skills level that allow students to progress to a higher level of competency in the…

Vorderstrasse, Ron; Siebert, Leo

279

Core Communications  

ERIC Educational Resources Information Center

|The website--it is where people go to find out anything and everything about a school, college, or university. In the relatively short life of the Internet, institutional websites have moved from the periphery to center stage and become strategically integral communications and marketing tools. As the flow of information accelerates and new…

Block, Greg; Ross, J. D.; Mulder, David

2011-01-01

280

Communicating Culture  

Microsoft Academic Search

By moving away from metaphors such as transparent-translation channels or omniscient agents, will it be possible to create communicating cultures with simple conversational agents, which might make errors but recognize (and fulfill) their expected role? By accomplishing this objective, intercultural experiences will be a lot more enjoyable, and many may feel that we'll be preserving the various unique cultures existing

Toru Ishida

2006-01-01

281

Quantum communication  

Microsoft Academic Search

Quantum communication, and indeed quantum information in general, has changed the way we think about quantum physics. In 1984 and 1991, the first protocol for quantum cryptography and the first application of quantum non-locality, respectively, attracted interest from a diverse field of researchers in theoretical and experimental physics, mathematics and computer science. Since then we have seen a fundamental shift

Nicolas Gisin; Rob Thew

2007-01-01

282

Political Communication  

Microsoft Academic Search

This course introduces major concepts of political communication in the era of digital media convergence. We assess the analytical force of these concepts and compare how they apply in the context of traditional mass media (television, radio, the press), and interactive online media, respectively. We review the concepts of the democratic performance of the media, mediatization, the public sphere, framing,

Kathleen Hall Jamieson; Craig Allen Smith; Stephen Bates; Jeffrey Abramson; Hugh Winebrenner; Richard Noyes; Joel Swerdlow

1988-01-01

283

Communicator, 1999.  

ERIC Educational Resources Information Center

|These four 1999 issues of the "Communicator" address reading needs of gifted children, middle schools, parenting the gifted, and the needs of young gifted children. Featured articles include: (1) "Academic Advocacy for the Forgotten Readers--Gifted and Advanced Learners" (Reading Task Force of the California Association for the Gifted); (2)…

Gosfield, Margaret, Ed.

1999-01-01

284

Experiment on Synchronous Timing Signal Detection from ISDB-T Terrestrial Digital TV Signal with Application to Autonomous Distributed ITS-IVC Network  

Microsoft Academic Search

A novel timing synchronizing scheme is proposed for use in inter-vehicle communication (IVC) with an autonomous distributed intelligent transport system (ITS). The scheme determines the timing of packet signal transmission in the IVC network and employs the guard interval (GI) timing in the orthogonal frequency divisional multiplexing (OFDM) signal currently used for terrestrial broadcasts in the Japanese digital television system

Yoshio Karasawa; Taichi Kumagai; Atsushi Takemoto; Takeo Fujii; Kenji Ito; Noriyoshi Suzuki

2009-01-01

285

Global methane emissions from terrestrial plants.  

PubMed

Recent measurements suggest that the terrestrial plant community may be an important source of methane with global contributions between 62 and 236 Tg CH4 y(-1). If true, terrestrial plants could rival wetlands as being the largest global source of methane forcing us to rethink the methane budget. While further measurements are needed to confirm the methane release rates from this source and their dependencies, in this work we use the preliminary measurements to assess the potential impact of the methane release from this source globally. Using novel techniques we extrapolate the initially reported chamber measurements to the global scale and calculate the global methane emissions from the terrestrial plant community to be in the range 20 to 69 Tg CH4 y(-1). The spread in emissions is largely due to the sensitivity of the global flux to the prescribed temperature dependence of the plant emission rate, which is largely unknown. The spread of calculated emissions is in good agreement with the upper limit imposed on the source during the late pre-industrial period, which we estimate to range from 25 to 54 Tg CH4 y(-1) during the years 0 to 1700 A.D. using the published atmospheric delta13CH4 record. In addition, if we assume that plant emissions have been constant at the mean value of 45 Tg CH4 y(-1), we find that the methane release from wildfires and biomass burning during the pre-industrial span 0-1000 A.D. must be near 12 Tg CH4 y(-1), which would be in better agreement with previous estimates of the pyrogenic source during this time than a methane budget missing the plant source. We conclude that methane release from the terrestrial plant community as presently understood does not require major innovations to the global methane budget. PMID:17612186

Butenhoff, Christopher L; Khalil, M Aslam Khan

2007-06-01

286

Terrestrial interface architecture (DSI\\/DNI)  

Microsoft Academic Search

The 64-kbit\\/s digital speech interpolation (DSI)\\/digital noninterpolation (DNI) equipment interfaces the TDMA satellite system with the terrestrial network. This paper provides a functional description of the 64-kbit\\/s DSI\\/DNI equipment built at Comsat Laboratories in conformance with the Intelsat TDMA\\/DSI system specification, and discusses the theoretical and experimental performance of the DSI system. Several DSI-related network and interface issues are discussed,

J. H. Rieser; M. Onufry

1985-01-01

287

Benhamycin, novel alkaloid from terrestrial Streptomyces sp  

Microsoft Academic Search

During our screening for bioactive natural compounds from microorganisms, a novel alkaloid has been isolated from a terrestrial Streptomyces sp. isolate NR12, and named as benhamycin (1). This was along with the known metabolites, uracil, thymine, p-hydroxybenzoic acid, 2?-deoxyuridin, tryptophol, indolyl-3-carboxylic acid, and indolyl-3-carbaldehyde. Chemical structure of the novel compound was determined by detailed analysis of its spectroscopic data (extensive

Mohamed Shaaban; Mohamed S. Abdel-Aziz

2007-01-01

288

Comparison Charts of Geological Processes: Terrestrial Planets  

NSDL National Science Digital Library

This chart presents information on the geological processes (volcanism, impact cratering, tectonics, and gradation) that have affected the Earth, Moon, and the terrestrial planets. Students compare the effects these processes have had on the Moon and planets. There is also a blank chart and a sheet of notes on the geological processes that may be used in conjunction with this chart. This chart is one of the activities for the Exploring Planets in the Classroom's Introduction to the Solar System.

289

Terrestrial adaptations in the Anomura (Crustacea: Decapoda)  

Microsoft Academic Search

Greenaway, P. 2003. Terrestrial adaptations in the Anomura (Crustacea: Decapoda). In: Lemaitre, R., and Tudge, C.C. (eds), Biology of the Anomura. Proceedings of a symposium at the Fifth International Crustacean Congress, Melbourne, Australia, 9-13 July 2001. Memoirs of Museum Victoria 60(1): 13-26. In this review, morphological, physiological and behavioural adaptations to life on land by anomurans are considered. The most

PETER GREENAWAY

2003-01-01

290

Long-period solar-terrestrial variability  

SciTech Connect

Studies aimed at extending the record of solar-terrestrial variability to longer periods are discussed in a critical review of US research from the period 1987--1990. Sections are devoted to the sunspot index, radioactive carbon studies, a potential climate connection between radiocarbon changes and the solar irradiance cycle, Be-10 studies, geological laminae, solar neutrino counts, and the construction of data sets. Also included is a selective bibliography. 66 refs.

Sonett, C.P. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

291

The Nitrogen Cycle in Terrestrial Ecosystems  

Microsoft Academic Search

The terrestrial nitrogen (N) cycle comprises soil, plant and animal pools that contain relatively small quantities of biologically\\u000a active N, in comparison to the large pools of relatively inert N in the lithosphere and atmosphere, but that nevertheless\\u000a exert a substantial influence on the dynamics of the global biogeochemical N cycle. After carbon (ca. 400 g kg?1) and oxygen (ca.

Ann McNeill; Murray Unkovich

292

Analysis of terrestrial solar radiation exergy  

Microsoft Academic Search

Based on Candau’s definition of radiative exergy, the exergy of the extraterrestrial and the terrestrial solar radiation are computed and compared by using the solar spectral radiation databank developed by Gueymard. The results show that within the spectrum region from 0.28 to 4.0 ?m, the total energy quality factor (i.e., the exergy-to-energy ratio) of extraterrestrial solar radiation is about 0.9292,

S. X. Chu; L. H. Liu

2009-01-01

293

Optical SETI with NASA's Terrestrial Planet Finder  

Microsoft Academic Search

NASA's space-borne nulling interferometer (the Terrestrial Planet Finder—TPF) will look for the traces of early life in the infrared spectra of extrasolar planets, beginning in roughly 2010. We point out that this instrument, as currently envisioned, will also be sensitive to deliberate laser transmissions from a technologically advanced civilization. A kilowatt-class infrared laser with a 10-m beam director would produce

Andrew Howard; Paul Horowitz

2001-01-01

294

Lunar reflections of terrestrial radio leakage  

NASA Astrophysics Data System (ADS)

Terrestrial radio leakage as reflected off the moon has been observed with the Arecibo antenna. The authors find that military radars and television transmitters are main contributors in the 150 - 500 MHz range, as predicted in the model of Sullivan et al. (1978). The earth indeed is revealing itself (eventually) to any interstellar eavesdropper with an Arecibo-like antenna at distances up to 30 light years, and with a Cyclops-like system up to fifteen times farther.

Sullivan, W. T., III; Knowles, S. H.

295

METI: Messaging to ExtraTerrestrial Intelligence  

NASA Astrophysics Data System (ADS)

Perhaps, after 50 years of listening to nothing but cosmic static, it is time to recognize that the time has come for humankind to take the lead in helping to end the Great Silence. Could it be that the future of SETI lies not in receiving, but rather in transmitting? In this chapter we introduce Messaging to Extra-Terrestrial Intelligence (METI) as a complementary science to SETI observations.

Zaitsev, Alexander L.

296

Plate tectonics on the terrestrial planets  

Microsoft Academic Search

Abstract Plate tectonics is largely controlled by the buoyancy distribution in oceanic lithosphere, which correlates well with the lithospheric age. Buoyancy,also depends,on compositional,layering resulting from pressure release partial melting under mid-ocean ridges, and this process is sensitive to pressure and temperature conditions which vary strongly between the terrestrial planets and also during the secular cooling histories of the planets. In

P. Van Thienen; N. j. Vlaar; A. p. Van Den Berg

297

The Carbon Cycles of Chinese Terrestrial Ecosystems  

NASA Astrophysics Data System (ADS)

The changes of Chinese terrestrial carbon storage depend not only on biogeochemical and climatological processes, but also on human activities and their interaction with carbon cycle. China,covering about 133.7 million hectares of forested land, has climate regimes ranging from tropical, to subtropical, temperate and cold temperate zones, and from southeast to northwest humid, semi arid and arid zones. A long history of agricultural exploitation, forest management practice, rapid change in land use, forestry policies, and economic growth suggest that Chinese terrestrial ecosystems play an important role in the global carbon cycles. Our recent results suggest that total carbon storage in Chinese terrestrial ecosystems is about 144 Pg C, including 7.3 Pg C in vegetation and 136.7 Pg C in soil. Chinese forests released about 0.68 Pg C between 1949 and 1980. Forest carbon storage has increased significantly after the late 1970s from 4.38 to 4.75 Pg C by 1998, mainly due to forest expansion and regrowth. Total organic carbon storage in soils in China is estimated to be about 70.31 Pg, representing 4.7%\\ of the world storage. The results also indicated that a soil organic carbon loss of 7.1 Pg was primarily due to human activity, in which the loss in organic horizons has contributed to 77%\\. This total loss of soil organic carbon in China induced by land use represents 9.5%\\ of the world's soil organic carbon decrease.

Peng, C.; Fang, J.; Guo, Z.; Wu, H.

2002-12-01

298

Determining quality of communication  

US Patent & Trademark Office Database

A method, computer-readable medium, and system for providing a quality measurement based on communications within a communication application. Communication attributes that include information associated with a user's communications are obtained. In embodiments, such communication attributes may pertain to communication duration and communication frequency. Upon obtaining communication attributes, a quality measurement may be determined based on the communication attributes. Such a quality measurement provides an indication of the quality of the user's communications. In embodiments, the quality measurement may be stored, communicated to a user, or implemented within a communication application.

Gollapudi; Sreenivas (Cupertino, CA); Halverson; Alan D. (Sunnyvale, CA); Kenthapadi; Krishnaram G. (Mountain View, CA)

2012-03-20

299

Developing Consistent Earth System Data Records for the Global Terrestrial Water Cycle: Focus on Shortwave and Longwave Radiative Fluxes  

NASA Astrophysics Data System (ADS)

The overall goal of this MEaSUREs Project is to develop consistent, long-term Earth System Data Records (ESDRs) for the major components of the terrestrial water cycle at a spatial resolution of 0.5 degree at climatic time scale. The shortwave (SW) and longwave (LW) radiative fluxes at the Earth's surface determine the exchange of energy between the land and the atmosphere and consequently, control the hydrologic cycle. Environmental satellites are considered as useful tools for providing information on surface radiative fluxes at various temporal and spatial scales, allowing improvement in estimation of terrestrial water and energy storage and oceanic heat fluxes. During the last two decades, significant progress has been made in assessing the Earth Radiation Balance from satellite observations. Yet, at present, satellite based estimates differ from each other and long term observations at global scale are not readily available. There is a need to utilize existing records of satellite observations and to improve currently available estimates. This requires updates to inference schemes so that new knowledge and most recent auxiliary information can be fully utilized. This paper reports on improvements introduced to an existing methodology to estimate shortwave (SW) radiative fluxes within the atmospheric system, on the development of a new inference scheme for deriving LW fluxes, the implementation of the approach with the ISCCP DX observations and improved atmospheric inputs for the period of 1983-2007, evaluation against ground observations, and comparison with independent satellite methods and numerical models. The resulting ESDRs from the entire MEaSUREs Project are intended to provide a consistent basis for estimating the mean state and variability of the land surface water cycle at a spatial scale relevant to major global river basins. Supported under NASA Grant NNX08AN40A, NRA/Research Opportunities in Space and Earth Sciences-2006.

Pinker, R. T.; Ma, Y.; Nussbaumer, E.

2011-12-01

300

Neural Communication  

NSDL National Science Digital Library

First you will explore the neuron. Then how neurons communicate with each other by exploring action potentials and neural transmission. Let's start with the neuron. Explore the neuron and fill out the worksheet by labeling each part of the neuron and giving a brief description of what it does. Structure of the Neuron (Upon entering the site go through each link at the top of the page from intro to terminal buttons) Now take a look ...

Johnson, Mrs.

2010-06-22

301

Military communications  

Microsoft Academic Search

Since its introduction in the late 1990s, the concept of network-centric operations to enable information sharing has been a fundamental element of the vision of military organizations throughout the world. As the complexity of operational environments increases, military communications network technologies must provide key characteristics such as self-organization and decentralization, which will speed information flow and increase situational awareness. In

T. Maseng; R. Landry; K. Young

2010-01-01

302

Corporate strategies for satellite communications  

NASA Astrophysics Data System (ADS)

Terrestrial and satellite broadcast communications technologies, while clearly providing tremendous benefits in many market sectors, present something of a challenge to the strategic planning bodies in most organizations. This is because there is no existing analog for the services in the organizations' telecommunications networks. The marketplace is therefore a confusing place for such organizations swamped as it is with competing service providers, technologies, and services, and their telecommunications strategies cannot cope with the opportunities because they have been founded on the exploitation of point to point connections. A mechanism for creating and bounding strategies which combines the rigor of structured analysis with a comprehensive categorization of strategic directions which has been successfully used to generate new paneuropean telecommunications strategies is presented.

Birch, David G. W.; Buck, S. Peter

1991-10-01

303

Rethinking the terrestrial water balance: Steps toward a comprehensive indicator framework  

NASA Astrophysics Data System (ADS)

Freshwater scarcity for humans and ecosystems is one of the most serious global challenges of the 21st century. Caused in part by human disturbance of the hydrologic cycle, patterns of water scarcity also reflect large, underlying variations in terrestrial water availability that precede human influence. In recent years, growing concerns about water scarcity have prompted the development and application of distributed, continental-to-global scale water balance models for water-resource assessment, fostering the important new sub-discipline of global hydrology. However, fundamental concepts of water availability have not kept pace with developments in modeling tools. To facilitate fundamental thinking and communication in this growing field, we introduce a new indicator framework based on a spatially distributed, time-dependent approach to the terrestrial water balance. The framework takes advantage of gridded climate, hydrology, and landscape data, is equally pertinent to dryland and humid regions of the world, and integrates traditional (runoff-based) and emerging perspectives on terrestrial water availability—including the blue/green water paradigm now gaining currency in the global water planning and management community. We derive the indicator framework from a general statement of the landscape water balance equation, and then illustrate the relevance of the framework to the extremely diverse hydroclimates of the conterminous United States.

Weiskel, P. K.; Wolock, D.; Zarriello, P. J.; Vogel, R. M.; Brandt, S. L.

2009-12-01

304

Assessing the Response of Terrestrial Ecosystems to Potential Changes in Precipitation  

NSDL National Science Digital Library

This peer-reviewed article from Bioscience journal is on the effects of changes in precipitation to the terrestrial ecosystem. Changes in Earth's surface temperatures caused by anthropogenic emissions of greenhouse gases are expected to affect global and regional precipitation regimes. Interactions between changing precipitation regimes and other aspects of global change are likely to affect natural and managed terrestrial ecosystems as well as human society. Although much recent research has focused on assessing the responses of terrestrial ecosystems to rising carbon dioxide or temperature, relatively little research has focused on understanding how ecosystems respond to changes in precipitation regimes. Here we review predicted changes in global and regional precipitation regimes, outline the consequences of precipitation change for natural ecosystems and human activities, and discuss approaches to improving understanding of ecosystem responses to changing precipitation. Further, we introduce the Precipitation and Ecosystem Change Research Network (PrecipNet), a new interdisciplinary research network assembled to encourage and foster communication and collaboration across research groups with common interests in the impacts of global change on precipitation regimes, ecosystem structure and function, and the human enterprise.

JAKE F. WELTZIN, MICHAEL E. LOIK, SUSANNE SCHWINNING, DAVID G. WILLIAMS, PHILIP A. FAY, BRENT M. HADDAD, JOHN HARTE, TRAVIS E. HUXMAN, ALAN K. KNAPP, GUANGHUI LIN, WILLIAM T. POCKMAN, M. REBECCA SHAW, ERIC E. SMALL, MELINDA D. SMITH, STANLEY D. SMITH, DAVID T. TISSUE, and JOHN C. ZAK (;)

2003-09-01

305

Wireless Communications  

NSDL National Science Digital Library

Wireless communications is an industry that is growing at an incredible rate. Cellular phones are the most obvious example of this trend; it is hard to go anywhere without seeing someone using one. Rapidly advancing technologies and lower prices are making this all possible. At the current pace, there seems to be no limit to what is possible in the wireless industry.To learn about the events that led up to present day wireless communications, this site offers a very informative history of telecommunications (1) that goes all the way back to the time of carrier pigeons. A good introduction to wireless networking can be found in this mini-tutorial (2). The best parts of this tutorial are the discussions of many recent wireless developments and technologies. There are a few interactive games and activities that are supposed to be instructive and entertaining, but some of them can be annoying. For the more technically savvy user, the third site (3) starts by describing many of the principles that drive current wireless systems. The second part examines the technologies that will be used in future generations of services. To build on this material, the third generation mobile communications systems (3G) is the central topic at 3G Newsroom (4), providing breaking news about the development of 3G technology. Additionally, the site has an excellent introduction to 3G, including its applications and specifications. One of the advancements that is paving the way toward 3G is Bluetooth, which is explained in great detail here (5). This technology is capable of very high data transfer rates, but there are some limitations, which are all discussed in the articles on the site. Although Bluetooth is raising plenty of interest, this recent news story (6) is creating more than its share of debate. It outlines a very controversial move by the FCC to allow the use of ultrawideband technology in commercial wireless applications. The author explains in simple terms why there are so many concerns about something that could revolutionize wireless systems. The evolution of the global system for mobile communications (GSM) is traced at GSM World (7). Here users can learn about the roots of the wireless industry as well as what is in store for the future. A special section addresses health concerns associated with mobile phone use. Radio was one of the earliest form of wireless communication, and the Invention of Radio (8) documents the people and events that made it what it is today. The stories of such famous scientists and inventors as Marconi, DeForest, and Armstrong are told in brief accounts, and there is even a link to the well known War of the Worlds radio broadcast.

Leske, Cavin.

2002-01-01

306

In-class demonstration using amateur radio satellites for the teaching of communications engineering at the Universiti Kebangsaan Malaysia  

Microsoft Academic Search

One of the most readily available demonstrations for teaching communications engineering is the amateur radio satellites orbiting the Earth. There are several advantages to using amateur satellites for classroom demonstration. The positions of the satellites are predictable, and, unlike terrestrial communications, the links are generally line of sight and more reliable. In general, the effects of the ionosphere are very

A. F. M. Zain

1994-01-01

307

Teppeki, selective insecticide about Bombus terrestris.  

PubMed

At a time when a highly controversial debate about the causes of the widespread deaths of bees is taking place all over Europe, which accused the agriculture and its practices with particular reference to the harmful effects of some insecticides, it seems important to point out as another insecticide, the Teppeki, can be selective about bumble and have a good compatibility with the activity of the apiaries. This insecticide has the active ingredient flonicamid (500 g/kg) belonging to a new chemical class, called pyridinecarboxamides: the product works systemic and is known as having a long lasting efficacy against all important aphid species. Bioagritest test facility of Pignola (PZ, Italy) has conducted in two successive production cycles an experimental trial on a tomato hydroponic cultivation within the Agricola Bonsai farm in Sibari (CS, Italy), whose objective was to measure the selectivity of flonicamid on Bombus terrestris, insects playing an important role in the pollination of certain species grown in greenhouse such as Tomato, Eggplant, Pepper and Cucumber. On the pollinated flower B. terrestris leaves some trace of its visit, a typical dark trademark: on the detection of the marking of flowers was based the testing program conducted by Bioagritest. Two thesis were compared: A, standard) treatment with a foliar insecticide, the neonicotinoide acetamiprid, normally used for control of aphids and whiteflies (unlike other neonicotinoides--imidacloprid and thiametoxam--quite selective about B. terrestris) and B, Teppeki) foliar treatment with Teppeki, to the maximum dose indicated on the label. The experimental design included the use of randomized blocks with 4 repetitions (4 plots/thesis with 100 plants each). In every thesis six B. terrestris hives were placed 2 days before treatment: the respective holes remained closed during the treatment and the 12 following hours. In order to verify the pollination, by the detection of the flower marking, 2 flowers per plant were observed, for a total of 200 flowers per plot. The measurements were made on the 3rd (I relief) and 8th day (II relief) after treatment. Statistical analysis was performed by the use of XLSTAT data analysis and statistical software. The analysis of collected data shows that flonicamid has a minor effect of interference with the activity of pollination by B. terrestris, compared to the standard used. 14 days after treatment, 3 hives per thesis were inspected in order to verify the status of the colonies (adults, larvae, eggs, pollen). The colonies appeared generally homogeneous as concerning the number of alive adults--100 for each--all at the end of the development cycle. There was no dead adult. Two colonies, one for thesis, presented evidence of eggs. All colonies had low stocks of pollen. Ultimately, treatment with Teppeki has not given any acute effect on B. terrestris, nor any effect of interference in respect of its pollination activity. PMID:20222598

Fanigliulo, Angela; Filì, Vittorio; Pacella, Rosa; Comes, Soccorsa; Crescenzi, Aniello

2009-01-01

308

Glaciopanspermia: Seeding the terrestrial planets with life?  

NASA Astrophysics Data System (ADS)

The question whether life originated on Earth or elsewhere in the solar system has no obvious answer, since Earth was sterilized by the Moon-forming impact and possibly also during the LHB, about 700 Ma after the formation of the solar system. Seeding by lithopanspermia has to be considered. Possible sources of life include Earth itself, Mars, Venus (if it had a more benign climate than today) and icy bodies of the solar system. The first step of lithopanspermia is the ejection of fragments of the surface into space, which requires achieving at least escape velocity. As the velocity distribution of impact ejecta falls off steeply, attention is drawn to bodies with lower escape velocities. Ceres has had, or still has, an ocean more than 100 km deep, with hydrothermal activity at its rocky core. The possible presence of life, its relative closeness to the terrestrial planets and Ceres' low escape velocity of 510 m/s suggest that Ceres could well be a parent body for life in the solar system.Icy impact ejecta - hence glaciopanspermia - from Ceres will be subject to evaporation of volatiles. Spores may be loosened by evaporation and enter the atmospheres of the terrestrial planets as micrometeorites.The seeding of the terrestrial planets from Ceres would result in (1) detection of life in the crustal layers of Ceres; (2) a commonality of Cerean life with Terran and possible Martian and Venusian life and (3) biomarkers of Cerean life, which might be found in the ice at the Moon's poles and on the surface of other main belt asteroids.

Houtkooper, Joop M.

2011-08-01

309

Plate Tectonics and Terrestrial Carbon Isotope Records  

NASA Astrophysics Data System (ADS)

In 2001, we reported a negative excursion in early-Aptian atmospheric ?13CO2 (? = -3.6 to -6.5‰), based on ?13C analyses of organic matter and land-plant isolates from coarsely-sampled Colombian estuarine and near-shore sediments. Here we present similar results for an Aptian section of the Arundel Clay (Potomac Group, central Maryland), which is well-known for its exceptional preservation of terrestrial plant materials. Sampling across 13 meters of sediment at ~10-cm intervals revealed a clear shift in the ?13C of terrestrial organic matter (n=153) and land-plant isolates (n=33) of ? = -2.3 and -2.9 ‰, respectively. The shift was observed within palynological Zone I, which is temporally well-correlated with our previous work. Using an empirical relationship between ?13Cplant and ?13Catm, we calculated ??13Catm = -2.1 to -2.6 ‰ during the early Aptian from the Arundel Clay shift. Given the probable composition of the early Cretaceous atmosphere, mass balance calculations favor a methane hydrate release as the cause of this excursion. In consideration of a mechanism for methane release, we calculated changes in global subduction indicated by the well-established and rapid 2-fold increase in seafloor production that was unique within the early Aptian compared to the last 144 million years. We show that increased frictional interaction between overriding and subducting plates caused uplift and compression sufficient to continuously destabilize a portion of the probable methane hydrate reservoir, thus creating a perturbation in the C-isotope record of the Aptian atmosphere, as reflected in the ?13C of terrestrial photosynthesizers. The Aptian methane release is a new example of mechanistic coupling between major tectonic events and the global biosphere.

Jahren, H.; Conrad, C.; Arens, N.

2005-12-01

310

Evolution of ore deposits on terrestrial planets  

NASA Astrophysics Data System (ADS)

Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars, but not submarine ferromanganese nodules and crusts which have precipitated in oxygenated seawater on earth.

Burns, R. G.

311

Aquatic predation alters a terrestrial prey subsidy.  

PubMed

Organisms with complex life histories (CLH) often cross habitat or ecosystem boundaries as they develop from larvae to adults, coupling energy flow between ecosystems as both prey (bottom-up) and consumers (top-down). Predation effects on one stage of this life cycle can therefore cascade across ecosystems, magnifying the impact of local predation. The majority of predation studies have assessed effects only on a local level, within the habitat of the predator. I used large outdoor stream mesocosms to test the hypothesis that predation in an aquatic habitat alters the magnitude and trophic structure of a prey assemblage in a terrestrial habitat. I also tested how a consumer in the terrestrial habitat (web-weaving spiders) responded to these changes in prey export. Two fish species were the predators (red shiner, Cyprinella lutrensis and orangethroat darter, Etheostoma spectabile) in an experiment with three treatments: both fish species monocultures plus a fishless control. Fish predation reduced aquatic insect emergence biomass by 50% compared to the fishless control and altered the trophic structure of the emergent community, reducing emerging insect predator biomass by 50%, but had no effect on other insect trophic groups. Spiders captured only insects that were unaffected by fish predation (mostly chironomids) and therefore did not respond numerically to overall changes in insect abundance or biomass. Patterns of insect emergence were largely driven by a strong negative relationship between fish and a predatory dragonfly (Pantala flavescens). The results of this experiment show that predation in one habitat can have strong effects on the biomass and trophic structure of subsidies entering adjacent habitats, resulting in contrasting predictions for the role of these subsidies in recipient food webs. In the absence of fish, aquatic habitats produced terrestrial insect communities with higher biomass (bottom-up potential) and a higher proportion of predators (top-down potential) than when fish were present. PMID:20503875

Wesner, Jeff Scott

2010-05-01

312

Communication externalities in cities  

Microsoft Academic Search

To identify communication externalities in French cities, we exploit a unique survey recording workplace communication of individual workers. Our hypothesis is that in larger and\\/or more educated cities, workers should communicate more. In turn, more communication should have a positive effect on wages. By estimating both an earnings and a communication equation, we find evidence of communication externalities. In larger

Sylvie Charlot; Gilles Duranton

2004-01-01

313

Communication Externalities in Cities  

Microsoft Academic Search

To identify communication externalities in French cities, we exploit a unique survey recording workplace communication of individual workers. Our hypothesis is that in larger and\\/or more educated cities, workers should communicate more. In turn, more communication should have a positive effect on individual wages. By estimating both an earnings and a communication equation, we find evidence of communication externalities. Being

Sylvie Charlot; Gilles Duranton

2003-01-01

314

Mobile communications - an overview  

Microsoft Academic Search

This article focuses on voice communications using mobile (cell) phones over mobile\\/cellular networks. The advances in processors, memory, signal processing, communication technologies, and several related techniques, personal mobile communications has witnessed tremendous growth. A typical mobile communication network consists of: mobile devices, BS, mobile switching centers, gateway mobile switching center. Cell phones communicate wirelessly with BSs. Base stations communicate with

S. R. Subramanya; B. K. Yi

2005-01-01

315

Ammonia transport by terrestrial and aquatic insects.  

PubMed

Ammonia, an end product from amino acid and nucleic acid metabolism, is highly toxic for most animals. This review will provide an update on nitrogen metabolism in terrestrial and aquatic insects with emphasis on ammonia generation and transport. Aspects that will be discussed include metabolic pathways of nitrogenous compounds, the origin of ammonia and other nitrogenous waste products, ammonia toxicity, putative ammonia transporters as well as ammonia transport processes known in insects. Ammonia transport mechanisms in the mosquito Aedes aegypti, the tobacco hornworm Manduca sexta and the locust Schistocerca gregaria will be discussed in detail while providing additional, novel data. PMID:22100291

Weihrauch, Dirk; Donini, Andrew; O'Donnell, Michael J

2011-11-10

316

Terrestrial Weathering Effects on Meteoritic Organics  

NASA Astrophysics Data System (ADS)

It is now well established for meteorites which fall in hot deserts that weathering brings about a readjustment of extra-terrestrial minerals. Assemblages which had achieved a level of equilibrium on the meteorite parent body now become unstable when exposed to new chemical and physical conditions[1] with FeO and Fe2+ minerals converting to Fe3+ species. Ash and Pillinger[2] have suggested that meteoritic organic matter may also become degraded in desert environments but this is less well substantiated and the processes involved far from clear. To investigate the effects of weathering on meteorite organics, five Saharan carbon-rich chondrites were studied by Mossbauer spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). Experimental conditions are given elsewhere. The samples chosen were El Djouf (CR), Acfer 186 and 187 (both CR, undoubtably related to one another and probably El Djouf, even though the latter was found some 500km away), Acfer 182 an anomalous chondrite (possibly in the CR clan) and Acfer 202 (a C03) . Table 1 shows the relative amounts (%) of iron containing assemblages in four of the meteorites analysed as determined by Mossbauer spectroscopy. El Djouf is substantially weathered with Acfer 187 and Acfer 182 perhaps less so but more weathered than Acfer 202. Fig 1 shows the pyrograms of four of the meteorites analyzed. El Djouf, Acfer 182 and Acfer 186 (=Acfer 187) yield very few discrete organic compounds. However Py-GCMS of unweathered CRs frequently detects a variety of organic fragments. Therefore it seems reasonable to suggest that, in the two CRs at least, macromolecular material has been present but has been degraded by weathering. Such a conclusion agrees well with the results from Mossbauer spectroscopy which indicate extensive oxidation in the CR meteorites. Acfer 202 clearly contains a number of organic components almost exclusively without oxygen, indicating that the macromolecule in Acfer 202 has escaped significant terrestrial oxidation. Again this is consistent with our Mossbauer results which show that Acfer 202 contains predominantly ferrous iron indicative of low levels of terrestrial oxidation. At face value we would argue that Acfer 202 is a relatively fresh carbonaceous chondrite worthy of detailed organic study. Clearly the above samples represent almost end-member cases where terrestrial weathering has either destroyed or has yet to affect the organic material present. Perhaps the most valuable information would come from a sample where oxidation of the macromolecule is at an intermediate stage. References: [1] Bland P. A. et al. (1995) LPS XXVI, 39. [2] Ash R. D. and Pillinger C. T. (1995) Meteoritics, 30, 85-92.

Sephton, M. A.; Bland, P. A.; Gilmour, I.; Pillinger, C. T.

1995-09-01

317

A new furostanol glycoside from Tribulus terrestris.  

PubMed

Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-20(22)-en-12-one-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations. PMID:20335931

Xu, Yajuan; Liu, Yonghong; Xu, Tunhai; Xie, Shengxu; Si, Yunshan; Liu, Yue; Zhou, Haiou; Liu, Tonghua; Xu, Dongming

2010-01-27

318

Two new furostanol saponins from Tribulus terrestris.  

PubMed

Two new furostanol saponins were isolated from the fruits of Tribulus terrestris L. Their structures were established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-3beta,26-diol-3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-beta-D-galactopyranoside (1) and 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-12-one-3beta,26-diol-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside (2) on the basis of spectroscopic data as well as chemical evidence. PMID:20496191

Xu, Ya-Juan; Xu, Tun-Hai; Zhou, Hai-Ou; Li, Bo; Xie, Sheng-Xu; Si, Yun-Shan; Liu, Yue; Liu, Tong-Hua; Xu, Dong-Ming

2010-05-01

319

Terrestrial Ages of Antarctic Meteorites: Up Date 1999  

Microsoft Academic Search

We are continuing our ongoing study of cosmogenic nuclides in Antarctic meteorites. In addition to the studies of exposure histories of meteorites, we study terrestrial ages and pairing of Antarctic meteorites and desert meteorites. Terrestrial ages of Antarctic meteorites provide information on meteorite accumulation mechanisms, mean weathering lifetimes, and influx rates. The determination of Cl-36 (half-life=3.01 x 105 y) terrestrial

K. Nishiizumi; M. W. Caffee; K. C. Welten

2000-01-01

320

Ohio River Basin energy study: Land use and terrestrial ecology  

NASA Astrophysics Data System (ADS)

Land use and terrestrial ecology data and analyses for the Ohio River Basin Energy Study (ORBES) region consisting of all of Kentucky, most of West Virginia, and substantial portions of Illinois, Indiana, Ohio, and Pennsylvania is presented. This 122 million acre region has a variety of land uses, which are summarized. Also discussed is the terrestrial ecology of the region (climate, physiography, soils, flora, fauna, and ecosystem dynamics). For the various ORBES energy development scenarios, land use conversion due to energy-related use was calculated, and impacts on terrestrial ecology were determined by application of the terrestrial ecosystem assessment methodology developed for ORBES.

Randolph, J. C.; Jones, W. W.

1981-09-01

321

Grazers: biocatalysts of terrestrial silica cycling.  

PubMed

Silica is well known for its role as inducible defence mechanism countering herbivore attack, mainly through precipitation of opaline, biogenic silica (BSi) bodies (phytoliths) in plant epidermal tissues. Even though grazing strongly interacts with other element cycles, its impact on terrestrial silica cycling has never been thoroughly considered. Here, BSi content of ingested grass, hay and faeces of large herbivores was quantified by performing multiple chemical extraction procedures for BSi, allowing the assessment of chemical reactivity. Dissolution experiments with grass and faeces were carried out to measure direct availability of BSi for dissolution. Average BSi and readily soluble silica numbers were higher in faeces as compared with grass or hay, and differences between herbivores could be related to distinct digestive strategies. Reactivity and dissolvability of BSi increases after digestion, mainly due to degradation of organic matrices, resulting in higher silica turnover rates and mobilization potential from terrestrial to aquatic ecosystems in non-grazed versus grazed pasture systems (2 versus 20 kg Si ha(-1) y(-1)). Our results suggest a crucial yet currently unexplored role of herbivores in determining silica export from land to ocean, where its availability is linked to eutrophication events and carbon sequestration through C-Si diatom interactions. PMID:24107532

Vandevenne, Floor Ina; Barão, Ana Lúcia; Schoelynck, Jonas; Smis, Adriaan; Ryken, Nick; Van Damme, Stefan; Meire, Patrick; Struyf, Eric

2013-10-09

322

Advanced Stirling conversion systems for terrestrial applications  

SciTech Connect

Sandia National Laboratories (SNLA) is developing heat engines for terrestrial Solar distributed Heat Receivers. SNLA has identified the Stirling to be one of the most promising candidates for the terrestrial applications. The free-piston Stirling engine (FPSE) has the potential to meet the DOE goals for both performance and cost. Free-piston Stirling activities which are directed toward a dynamic power source for the space application are being conducted. Space power system requirements include high efficiency, very long life, high reliability and low vibration. The FPSE has the potential for future high power space conversion systems, either solar or nuclear powered. Generic free-piston technology is currently being developed for use with a residential heat pump under an Interagency Agreement. Also, an overview is presented of proposed conceptual designs for the Advanced Stirling Conversion System (ASCS) using a free-piston Stirling engine and a liquid metal heat pipe receiver. Power extraction includes both a linear alternator and hydraulic output capable of delivering approximately 25 kW of electrical power to the electric utility grid. Target cost of the engine/alternator is 300 dollars per kilowatt at a manufacturing rate of 10,000 units per year. The design life of the ASCS is 60,000 h (30 y) with an engine overhaul at 40,000 h (20 y). Also discussed are the key features and characteristics of the ASCS conceptual designs.

Shaltens, R.K.

1987-01-01

323

Fuel cells for extraterrestrial and terrestrial applications  

SciTech Connect

The fuel cell is a nineteenth century invention and a twentieth century technology development. Due to the high power and energy density, high efficiency, reliability, and production of pure water, hydrogen-oxygen fuel cell systems have no competition as auxiliary power sources for space vehicles. The alkaline fuel cell system is a well developed and proven technology for this application. The solid polymer electrolyte system may be its future competitor. The energy crisis of 1973 stimulated research, development and demonstration of the phosphoric acid, molten carbonate, solid oxide and solid polymer electrolyte fuel cell systems using natural gas, petroleum or coal derived hydrogen (and carbon monoxide for the high temperature systems) for terrestrial applications. The direct methanol-air fuel cell is still an electrochemist's dream. Though considerable technological advances have been made, the present price of crude oil, and the high capital costs and limited lifetime of fuel cell systems impede their terrestrial applications in the developed countries. Conversely, the potential for lower capital costs of labor intensive manufacturing processes and the relatively higher fossil fuel prices make these systems more attractive for such applications in the developing countries. 11 refs.

Srinivasan, S.

1987-01-01

324

Bioaccumulation of heavy metals in terrestrial invertebrates.  

PubMed

In this literature study, accumulation data of metals in terrestrial invertebrates were collected and compared (Arthropoda and Lumbricidae). Based on total soil concentrations and body concentrations, regression equations were calculated for each metal (Cd, Cu, Pb and Zn) and each taxonomic group. We also tried to find out whether or not accumulation levels of metals in Lumbricidae are representative for all of the studied terrestrial invertebrates. Taxonomic groups could be ordered according to the extent of metal accumulation. Significant differences in accumulation levels of a factor 2-12 were found between taxonomic groups. Overall, metal concentrations were high in Isopoda and low in Coleoptera. The concentrations in Lumbricidae were in between. It should be kept in mind that the data for Lumbricidae were mainly derived from laboratory experiments, while the data for other groups were derived from field studies. The internal Pb, Cd and Cu concentration increased with the soil concentration for most taxonomic groups in the order Pb > Cd > Cu. Body concentrations of Zn were quite constant over a range of soil concentrations. The differences in accumulation level between taxonomic groups show the relevance of including detailed information on feeding behaviour in risk assessment for invertebrate-eating animals. PMID:11428146

Heikens, A; Peijnenburg, W J; Hendriks, A J

2001-01-01

325

Terrestrial applications of the heatpipe power system  

SciTech Connect

A terrestrial reactor that uses the same design approach as the Heatpipe Power System (HPS) may have applications both on earth and on other planetary surfaces. The baseline HPS is a potential, near-term, low-cost space fission power system. The system will be composed of independent modules, and all components operate within the existing database. The HPS has relatively few system integration issues; thus, the successful development of a module is a significant step toward verifying system feasibility and performance estimates. A prototypic, refractory-metal HPS module is being fabricated, and testing is scheduled to begin in November 1996. A successful test will provide high confidence that the HPS can achieve its predicted performance. An HPS incorporating superalloys will be better suited for some terrestrial or planetary applications. Fabrication and testing of a superalloy HPS module should be less challenging than that of the refractory metal module. A superalloy HPS core capable of delivering > 100 kWt to a power conversion subsystem could be fabricated for about $500k (unfueled). Tests of the core with electric heat (used to simulate heat from fission) could demonstrate normal and off-normal operation of the core, including the effects of heatpipe failure. A power conversion system also could be coupled to the core to demonstrate full system operation.

Houts, M.G.; Poston, D.I.

1997-02-01

326

Fuel cells for extraterrestrial and terrestrial applications  

SciTech Connect

The fuel cell is a nineteenth century invention and a twentieth century technology development. Hydrogen-oxygen fuel cell systems have no competition as auxiliary power sources for space vehicles. The alkaline fuel cell system is a proven technology for this application. The solid polymer electrolyte system may be its future competitor. The energy crisis of 1973 stimulated research, development, and demonstration of the phosphoric acid, molten carbonate, solid oxide, and solid polymer electrolyte fuel cell systems using natural gas, petroleum, or coal-derived hydrogen (and carbon monoxide for the high temperature systems) for terrestrial applications. The direct methanol-air fuel cell is still an electrochemist's dream. The present price of crude oil, and the high capital costs and limited lifetime of fuel cell systems impede their terrestrial applications in the developed countries. Conversely, the potential for lower capital costs of labor intensive manufacturing processes and the higher fossil fuel prices make these systems more attractive for such applications in the developing countries.

Srinivasan, S.

1989-02-01

327

Tectonic evolution of the terrestrial planets.  

PubMed

The style and evolution of tectonics on the terrestrial planets differ substantially. The style is related to the thickness of the lithosphere and to whether the lithosphere is divided into distinct, mobile plates that can be recycled into the mantle, as on Earth, or is a single spherical shell, as on the moon, Mars, and Mercury. The evolution of a planetary lithosphere and the development of plate tectonics appear to be influenced by several factors, including planetary size, chemistry, and external and internal heat sources. Vertical tectonic movement due to lithospheric loading or uplift is similar on all of the terrestrial planets and is controlled by the local thickness and rheology of the lithosphere. The surface of Venus, although known only at low resolution, displays features both similar to those on Earth (mountain belts, high plateaus) and similar to those on the smaller planets (possible impact basins). Improved understanding of the tectonic evolution of Venus will permit an evaluation of the relative roles of planetary size and chemistry in determining evolutionary style. PMID:17741171

Head, J W; Solomon, S C

1981-07-01

328

Modulation and coding for satellite and space communications  

NASA Astrophysics Data System (ADS)

Several modulation and coding advances supported by NASA are summarized. To support long-constraint-length convolutional code, a VLSI maximum-likelihood decoder, utilizing parallel processing techniques, which is being developed to decode convolutional codes of constraint length 15 and a code rate as low as 1/6 is discussed. A VLSI high-speed 8-b Reed-Solomon decoder which is being developed for advanced tracking and data relay satellite (ATDRS) applications is discussed. A 300-Mb/s modem with continuous phase modulation (CPM) and codings which is being developed for ATDRS is discussed. Trellis-coded modulation (TCM) techniques are discussed for satellite-based mobile communication applications.

Yuen, Joseph H.; Simon, Marvin K.; Pollara, Fabrizio; Divsalar, Dariush; Miller, Warner H.; Morakis, James C.; Ryan, Carl R.

1990-07-01

329

Economy of modularized communication platforms and satellite clusters  

NASA Astrophysics Data System (ADS)

Results from an ESA cost-benefits analysis of modularized communication platforms and satellite clusters are reviewed. Attention was given to a reference satellite based on current technology, and advanced candidates for television broadcasting from a 19 deg W GEO modularized units and clusters. Both the Ariane and the Shuttle were considered as the launch vehicles for large, autonomous satellites, co-orbiting cluster units, or modular platofrms to be assembled in GEO. The analyses included development of performance and specific requirements, and cost comparison. Cost components comprised the spacecraft, constant costs, space segment costs, operations, and total system costs for a direct television broadcast system for Europe. An Ariane-launched modular platform was projected to cost 60% of the reference system, with break-even occurring at the addition of the third payload module.

Kleinau, W.; Nauck, J.; Hansell, P.

1982-09-01

330

Space Communication  

NASA Astrophysics Data System (ADS)

As the space era approaches, the importance of including space science in the general curriculum and communicating space science to the general public is becoming extremely important. The paper, points out that the inclusion of more space education in the school curriculum and to the general public will increase awareness and interest in the new developments of space exploration. The paper covers some of the many science communication projects under taken by students in the UK. One such success was the contribution to National Science Week by the University of Leicester in conjunction with UK Students for the Exploration and Development of Space (UKSEDS - a national body of students promoting space education). Children between the ages of 9-12 were taught about the solar system using enjoyable experiments. The paper will also cover other UKSEDS activities and projects. On a more worldwide scale `Under African Skies' is a fairly new and immensely exciting project (part of Cosmos Education): the participants last year including UKSEDS members travelled from school to school in Africa helping teachers and taking part in classes, including many in astronomy and physics. The paper also explains the benefits of the National Space Centre in the UK, the involvement of the University of Leicester in SSETI (Student Space Exploration and Technology Initiative) and Space School.

Patel, Bhavini

2002-01-01

331

Creativity in clinical communication: from communication skills to skilled communication.  

PubMed

Medical Education 2011: 45: 217-226 Objectives? The view that training in communication skills produces skilled communication is sometimes criticised by those who argue that communication is individual and intuitive. We therefore examine the validity of the concept of communication as a skill and identify alternative principles to underpin future development of this field. Methods? We critically examine research evidence about the nature of clinical communication, and draw from theory and evidence concerning education and evaluation, particularly in creative disciplines. Results? Skilled communication cannot be fully described using the concept of communication skills. Attempts to do so risk constraining and distorting pedagogical development in communication. Current education practice often masks the difficulties with the concept by introducing subjectivity into the definition and assessment of skills. As all clinical situations differ to some extent, clinical communication is inherently creative. Because it is rarely possible to attribute specific effects to specific elements of communication, communication needs to be taught and evaluated holistically. Conclusions? For communication teaching to be pedagogically and clinically valid in supporting the inherent creativity of clinical communication, it will need to draw from education theory and practice that have been developed in explicitly creative disciplines. PMID:21299597

Salmon, Peter; Young, Bridget

2011-03-01

332

[Communication and iatrogenesis through communication].  

PubMed

Human intercommunication means transfer of information through many channels, with codes that have biological and socio-cultural determinism. The biological determinism is identifiable through the development of the phonetics and ergomotricity functions, through the possibility of perception of the sensorial organs. The channels of human intercommunication can be verbal, linguistic (the most specialised channel), and nonverbal, extra linguistic channels (mimics, written model, drawing, walking), that are effectively implicated in defining a direct dialogue between the doctor and the patient, completing and emphasising the communication. PMID:12092222

Mor?ra?u, C; Brînz?, M; Bort?, C; Mor?ra?u, G; Boza, C; Rogojin?, O

333

Developing Consistent Earth System Data Records for the Global Terrestrial Water Cycle: Focus on Shortwave and Longwave Radiative Fluxes  

NASA Astrophysics Data System (ADS)

The overall goal of the MEaSUREs activity titled: "Developing Consistent Earth System Data Records for the Global Terrestrial Water Cycle" is to develop consistent, long-term Earth System Data Records (ESDRs) for the major components of the terrestrial water cycle at a climatic time scale. The shortwave (SW) and longwave (LW) radiative fluxes at the Earth's surface determine the exchange of energy between the land and the atmosphere are the focus of this presentation. During the last two decades, significant progress has been made in assessing the Earth Radiation Balance from satellite observations. Yet, satellite based estimates differ from each other and long term satellite observations at global scale are not readily available. There is a need to utilize existing records of satellite observations and to improve currently available estimates. This paper reports on improvements introduced to an existing methodology to estimate shortwave (SW) radiative fluxes within the atmospheric system, on the development of a new inference scheme for deriving LW fluxes, the implementation of the approach with the ISCCP DX observations and improved atmospheric inputs for the period of 1983-2007, evaluation against ground observations, and comparison with independent satellite methods and numerical models. The resulting ESDRs from the entire MEaSUREs Project are intended to provide a consistent basis for estimating the mean state and variability of the land surface water cycle at a spatial scale relevant to major global river basins. MEaSUREs Project "Developing Consistent Earth System Data Records for the Global Terrestrial Water Cycle" Team Members: E. F. Wood (PI)1, T. J Bohn2, J. L Bytheway3, X. Feng4, H. Gao2, P. R.Houser4 (CO-I), C. D Kummerow3 (CO-I), D. P Lettenmaier2 (CO-I), C. Li5, Y. Ma5, R. F MacCracken4, M. Pan1, R. T Pinker5 (CO-I), A. K. Sahoo1, J. Sheffield1 1. Dept of CEE, Princeton University, Princeton, NJ, USA. 2. Dept of CEE, University of Washington, Seattle, WA, USA. 3. Dept of Atmospheric Science, Fort Collins, CO, USA. 4. Dept of Geography and GeoInformation Scie., George Mason University, Fairfax, VA, USA. 5. Dept of Meteorology, University of Maryland, College Park, MD, USA.

Pinker, R. T.; Ma, Y.; Nussbaumer, E. A.

2012-04-01

334

Ice Age terrestrial carbon changes revisited  

NASA Astrophysics Data System (ADS)

N. Shackleton (1977) first proposed that changes in the marine ?13C record (??13C) could be used to infer ice age changes in carbon storage on land. The previously published best estimate from the marine record is equivalent to about 490 Gt (0.32 ??13C). However, Adams et al. (1990) utilized a pollen database to estimate a 1350 Gt change in carbon storage, which would cause a ??13C of about 0.90‰. The nearly trillion ton difference in estimates amounts to almost half of the total carbon stored on land. To address the nature of this discrepancy, I have reexamined the terrestrial carbon record based on a new pollen database compiled by R. Webb and the Cooperative Holocene Mapping Project (COHMAP) group. I estimate about 750-1050 Gt glacial-interglacial change in terrestrial carbon storage, with the range reflecting uncertainties in carbon storage values for different biomes. Additional uncertainties apply to rainforest and wetland extent and presence of C4 plants, which have a significantly different isotopic signature than C3 plants. Although some scenarios overlap a new estimate of carbon storage based on the oceanic ??13C record (revised to 0.40‰ and 610 Gt), most estimates seem to fall outside the envelope of uncertainty in the marine record. Several possible explanations for this gap involve: (1) a missing sink may be involved in land-sea carbon exchange (e.g., continental slopes); (2) the geochemistry of the exchange process is not understood; (3) carbon storage by biome may have changed under ice age boundary conditions; or (4) the standard interpretation of whole ocean changes in the marine ?13C record requires reevaluation. This latter conclusion receives some support from comparison of the ?13C records for ?18O Stages 2 and 6. For the Stage 6 glacial, the ?13C changes are 50-60% larger than for the Stage 2 glacial. Yet implications of increased aridity are not supported by longterm trends in atmospheric dust loading. To summarize, the above analysis implies that, despite the uncertainties remaining in estimates of terrestrial carbon storage changes, a case can be made that our understanding of the transfer process is incomplete and that the eventual explanation may require clarification of factors affecting the marine ?13C record.

Crowley, Thomas J.

1995-09-01

335

Terrestrial plant biopolymers in marine sediments  

NASA Astrophysics Data System (ADS)

The vascular land plant biopolymers lignin and cutin were surveyed in the surface sediments of coastal and open ocean waters by controlled alkaline CuO oxidation/reaction. Two contrasting oceanic regimes were studied: the northwest Mediterranean (NWM) Sea, which receives significant particulate terrigenous debris through riverine discharge; and the northeast Atlantic (NEA) Ocean, with poorly characterised terrestrial carbon inputs. In the NWM products of lignin and cutin co-occurred at all stations, elevated levels (ca. 0.5-3.0 mg lignin phenols/100 mg organic carbon; ca. 0.01-0.09 mg cutin acids/100 mg organic carbon) were observed for near-shore deltaic and shelf sediments. The influence of terrestrial land plant inputs extended across the shelf and through the slope to the abyssal plain, providing molecular evidence for advective offshore transfer of terrestrial carbon. Mass balance estimates for the basin suggest riverine inputs account for the majority of surface sedimentary lignin/cutin, most of which (>90%) is deposited on the shelf. Products of CuO oxidation of lignin and cutin were also detected in NEA surface sediments, at levels comparable to those observed for the NWM continental slope, and were detectable at low concentrations ( ca . 0.5 g g -1 in the sediments of the abyssal plains (>4,000 m depth). While atmospheric deposition of lignin/cutin-derived material cannot be discounted in this open ocean system, lateral advective transfer of enriched shelf sediments is inferred as a possible transport process. A progressive enrichment in cutin-derived material relative to lignin was observed offshore, with evidence of an increase in the degree of oxidative alteration of lignin residues. To account for these observations, preferential offshore transport of finer and more degraded material is proposed. Nonspecific oxidation products dominated the gas chromatograms of NEA sediments, which appear to originate from marine sources of sedimentary organic carbon. Preliminary mass balance calculations applied to the global ocean margin suggest riverine sources of both particulate lignin and cutin are important and that most (>95%) deposition of recognisable land plant biopolymers occurs in shelf seas.

Gough, Mark A.; Fauzi, R.; Mantoura, C.; Preston, Martin

1993-03-01

336

Terrestrial analogs of possible Martian habitats  

NASA Astrophysics Data System (ADS)

Four environmental factors are responsible for the apparent absence of life on or near the surface of Mars: radiation, reactive oxidants, aridity and low temperature. The three latter factors are also present in terrestrial environments that approximate, although do not reach, the intensity of Martian conditions. Nor do they occur together in the same environments, yet they allow studying the response of microorganisms separately to each of these environmental factors. 1. Most laboratory experiments on radiation "resistance" deal with the ability of microorganisms to repair (in a radiation-free environment) previously suffered radiation damage. Little is known on the response to continuous high radiation environments. 2. Mars-like soils with reactive oxidants have recently (2004) been discovered in the most arid regions of the Atacama Desert. 3. Extreme aridity (absence of liquid water) has been studied in the Negev, Gobi and other deserts. In these habitats the sole primary producer worldwide is the cyanobacterium Chroococcidiopsis. This organism tolerates total desiccation for decades and upon wetting it resumes full activity within a few minutes. However, it utilizes only liquid water, not water vapor from the atmosphere. Both heterotrophic and photosynthetic bacteria (primary producers) reach their limit of existence in the extreme arid core of the Atacama Desert, possibly the driest place on Earth. 4. Extreme cold, per se, is not harmful to life: organisms in frozen state can be preserved for very long times. On Earth, "psychrophiles" (cold adapted microorganisms) live in oceans and lakes, in thermally stable aquatic environments with temperature optima around +5o C, and are unable to tolerate temperatures above +15o C. Extreme cold conditions occur only in non-aquatic (terrestrial) environments. Here the limiting factor is not low temperature, but rather the lack of high temperature necessary to drive metabolic processes. Microorganisms of these habitats are not well-adapted psychrophiles but psychrotolerant mesophiles with temperature optima around +20o C. In the thermally unstable environment of cryptoendolithic microorganisms inside rocks of the Antarctic cold desert the yearly temperature fluctuates from -45o C to (exceptionally) +22o C. In the thermally stable permafrost (frozen soil) the temperature is ca. -10o C in Siberia and -20o C to -30o C in Antarctica. The above environments will be discussed to some detail accompanied by slides of landscapes, close-ups and micrographs. The relevance of information from terrestrial analogs to biology of Mars will be critically discussed.

Friedmann, E. I.

337

Impact ejecta emplacement on terrestrial planets  

NASA Astrophysics Data System (ADS)

Impact cratering is one of the most fundamental processes responsible for shaping the surfaces of solid planetary bodies. One of the principal characteristics of impact events is the formation and emplacement of ejecta deposits, an understanding of which is critical for planetary exploration. Current models of ejecta emplacement, however, do not account for several important observations of ejecta deposits on the terrestrial planets, in particular, the presence of more than one layer of ejecta. Furthermore, there is also no universal model for the origin and emplacement of ejecta on different planetary bodies. We present a unifying working hypothesis for the origin and emplacement of ejecta on the terrestrial planets, in which the ejecta are emplaced in a multi-stage process. The generation of the continuous ejecta blanket occurs during the excavation stage of cratering, via the conventional ballistic sedimentation and radial flow model. This is followed by the emplacement of more melt-rich, ground-hugging flows - the "surface melt flow" phase - during the terminal stages of crater excavation and the modification stage of crater formation. Minor fallback occurs during the final stages of crater formation. Several factors will affect the final morphology and character of ejecta deposits. The volatile content and cohesiveness of the uppermost target rocks will significantly affect the runout distance of the ballistically emplaced continuous ejecta blanket, with impact angle also influencing the overall geometry of the deposits (e.g., the production of the characteristic butterfly pattern seen in very oblique impacts). Ejecta deposited during the surface melt flow stage is influenced by several factors, most importantly planetary gravity, surface temperature, and the physical properties of the target rocks. Topography and angle of impact play important roles in determining the final distribution of surface melt flow ejecta deposits with respect to the source crater. This working hypothesis of ballistic sedimentation and surface melt flow provides a framework in which observations of ejecta at impact craters can be compared and placed in the context of the respective terrestrial planets.

Osinski, Gordon R.; Tornabene, Livio L.; Grieve, Richard A. F.

2011-10-01

338

Primordial Terrestrial Xe from the Viewpoint of CFF-Xe  

NASA Astrophysics Data System (ADS)

We have already reported [7, 23] on the non-linear isotope mass-fractionation of fission Xe by migration of the precursors I, Te, Sn, and Sb and simultaneous fission of heavy nuclei. Xe with anomalous isotopic pattern was found in a number of meteorites and terrestrial materials and was named CFF-Xe (Chemically Fractionated Fission Xe). It is characterized by an up eightfold ^132Xe and ^131Xe excesses coupled with smaller ^134Xe and ^129Xe excesses. The present work is aimed to estimate the role of CFF-Xe in the terrestrial lithosphere and specifically deals with the problem of the isotopic composition of primordial terrestrial Xe. Due to variations of the migration conditions the isotopic structure of CFF-Xe is not well established and is even not reproducible in the same rock [2]. Nevertheless, we have tried to estimate the composition of CFF-Xe by investigating all available isotopic data of Xe of presumable mantle origin. This is Xe in MORB [29, 1, 12] and ocean island glasses [1, 28], in diamonds [17], in volcanic rocks [29, 8, 9, 21], in volcanic glasses from pillow basalts [16, 6], continental igneous rocks [1, 24, 10, 22], carbonatites and granitoids [1] as well as Xe in natural gases [3, 24, 11, 4, 15]. All data are plotted Fig. 1 where we also suggest end members of the observed scattering. Optimized slopes of CFF-lines are shown as well as the position of the initial points which we regard as primordial terrestrial Xe (Xe0). The isotopic composition of CFF-Xe and Xe0 are given in Tab. 1. The abundances of ^124Xe and ^126Xe in mantle derived samples are very uncertain, but since ^128Xe/^130Xe in Xea and Xe0 is very similar we propose the same ^124Xe/^130Xe and ^126Xe/^130Xe ratios for both Xea and Xe0. If so, AVCC-Xe is simply Xe0 with an admixture of L-Xe, and atmospheric xenon Xea consists of Xe0, CFF-Xe and a small amount of fission Xe (92.5%Xe0 + 5.3%CFF-Xe + 2.2%XeF). Thus, a number of old problems in xenology are removed. The hypothetic components U-Xe or atmosphere-like Xe are not required anymore. Instead, experimentally identified Xe0 can be regarded as primordial terrestrial Xe with an isotopic composition close to AVCC-Xe. Isotopic mass-fractionation is not needed to be involved. Concerning ^129Xe in the mantle, it seems to be part of CFF-Xe rather than the product of primordial 129I decay. This interpretation is supported by the observation of 129I excesses near uranium deposits that provides an additional argument in favor the CFF-Xe hypothesis [5, 14]. This work is supported by INTAS # 94-2397. References: [1] Allegre C. J. et al. (1983) Nature, 303, 762-766. [2] Azuma Sh. et al. (1993) EPSL, 114, 341-352. [3] Boulos M. S. et al. (1971) Science, 174, 1334-1336. [4] Caffee M. W. et al. (1988) AGU Meeting in San Francisco, reprint. [5] Fabrika-Martin J. et al. (1989) GCA, 53, 1817-1823.[6] Hiyagon H. et al. (1992) GCA, 56, 1301-1316. [7] Jessberger E. K. et al. (1992) LPS XXIII, 615-616. [8] Kaneoka I. et al. (1978) EPSL, 39, 382-386. [9] Kaneoka I. et al. (1983) EPSL, 66, 427-437. [10] Levsky L. K. (1993) personal communication. [11] Lin W. J. and Manuel O. K. (1987) Geochem. J., 2, 197-207. [12] Marty B. (1989) EPSL, 94, 45-56. [13] Meshik A. P. (1988) Ph.D. thesis , Vernadsky Institute, Moscow, 211 pp., in Russian. [14] Michelot J. L. et al. (1989) GCA, 53, 1803-1815. [15] Murty S. V. S. (1992) Chem. Geol., 94, 229-240. [16] Ozima M. and Podosek F. A. (1983) Noble Gas Geochemistry, Cambridge Univ., 367 pp. [17] Ozima M. and Zashu S. (1991) EPSL, 105, 13-27. [18] Ozima M. et al. (1983) EPSL, 62, 24-40. [19] Pepin R. O. (1993) preprint. [20] Phinney D. et al. (1978) JGR, 83, 2313-2319. [21] Poreda J. and Farley K. A. (1992) EPSL, 113, 129-144. [22] Schafer K. et al. (1993) Jahresbericht, 244-245, MPI fur Kernphysik, Heidelberg. [23] Shukolyukov Yu. A. et al. (1994) GCA, 58, 3075-3092. [24] Smith S. P. (1984) GCA, 48, 1033-1041. [25] Smith S. P.and Reinolds J. H. (1981) EPSL, 54, 236-238. [26] Staudacher Th. (1987) Nature, 325, 605-609. [27] Staudacher Th. and Allegre C. J. (1982) EPSL, 60, 389-406.

Meshik, A. P.; Shukolyukov, Yu. A.; Jessberger, E. K.

1995-09-01

339

Microalgal and terrestrial transport biofuels to displace fossil fuels  

Microsoft Academic Search

Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn, sugar beet or wheat and biodiesel from rapeseed. When terrestrial biofuels are to

Lucas Reijnders

2009-01-01

340

Integrated broadband antenna for USB digital Terrestrial TV receiver  

Microsoft Academic Search

A built-in antenna for a USB key like digital terrestrial TV receiver allowing free to air reception of digital terrestrial TV on a computer PC has been designed, realized and tested. The housing of the compact receiver is used as part of the antenna. The antenna design is optimized so that it covers the whole UHF frequency bandwidth with good

P. Minard; J.-F. Pintos; A. Louzir

2006-01-01

341

GGSP: Realisation and maintenance of the Galileo Terrestrial Reference Frame  

Microsoft Academic Search

The realisation and maintenance of a Galileo Terrestrial Reference Frame (GTRF) is the main function of the Galileo Geodetic Service Provider (GGSP). The GTRF shall be compatible with the latest International Terrestrial Reference Frame (ITRF) within a precision level of 3cm (2 sigma). The connection to the ITRF is realized and validated by stations of the International GNSS Service (IGS)

G. Gendt; Z. Altamimi; R. Dach; W. Söhne; T. Springer

2011-01-01

342

Impact of geoengineering schemes on the terrestrial biosphere  

Microsoft Academic Search

Climate stabilization via “Geoengineering” schemes seek to mitigate climate change due to increased greenhouse gases by compensating reduction in solar radiation incident on earth's surface. In this paper, we address the impact of these climate stabilization schemes on terrestrial biosphere using equilibrium simulations from a coupled atmosphere-terrestrial biosphere model. Climate stabilization would tend to limit changes in vegetation distribution brought

B. Govindasamy; S. Thompson; P. B. Duffy; K. Caldeira; C. Delire

2002-01-01

343

Impact of geoengineering schemes on the terrestrial biosphere  

Microsoft Academic Search

Climate stabilization via ``Geoengineering'' schemes seek to mitigate climate change due to increased greenhouse gases by compensating reduction in solar radiation incident on earth's surface. In this paper, we address the impact of these climate stabilization schemes on terrestrial biosphere using equilibrium simulations from a coupled atmosphere-terrestrial biosphere model. Climate stabilization would tend to limit changes in vegetation distribution brought

B. Govindasamy; S. Thompson; P. B. Duffy; K. Caldeira; C. Delire

2002-01-01

344

Interannual variation of carbon exchange fluxes in terrestrial ecosystems  

Microsoft Academic Search

A global prognostic physiologically based model of the carbon budget in terrestrial ecosystems, the Frankfurt Biosphere Model (FBM), is applied to simulate the interannual variation of carbon exchange fluxes between the atmosphere and the terrestrial biosphere. The data on climatic forcing are based on Cramer and Leemans climate maps; the interannual variation is introduced according to records of temperature anomalies

Jürgen Kindermann; Gudrun Würth; Gundolf H. Kohlmaier; Franz-W. Badeck

1996-01-01

345

The Movement of Aquatic Mercury Through Terrestrial Food Webs  

Microsoft Academic Search

Mercury has contaminated rivers worldwide, with health consequences for aquatic organisms and humans who consume them. Researchers have focused on aquatic birds as sentinels for mercury. However, trophic transfer between adjacent ecosystems could lead to the export of aquatic mercury to terrestrial habitats. Along a mercury-contaminated river in Virginia, United States, terrestrial birds had significantly elevated mercury levels, similar to

Daniel A. Cristol; Rebecka L. Brasso; Anne M. Condon; Rachel E. Fovargue; Scott L. Friedman; Kelly K. Hallinger; Adrian P. Monroe; Ariel E. White

2008-01-01

346

Climate control of terrestrial carbon exchange across biomes and continents  

Microsoft Academic Search

Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net

Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; Luis Aires; John D. Albertson; Christof Ammann; M. Altaf Arain; Alessandro C. de Araujo; Marc Aubinet; Mika Aurela; Zoltán Barcza; Alan Barr; Paul Berbigier; Jason Beringer; Christian Bernhofer; Andrew T. Black; Paul V. Bolstad; Fred C. Bosveld; Mark S. J. Broadmeadow; Nina Buchmann; Sean P. Burns; Pierre Cellier; Jingming Chen; Jiquan Chen; Philippe Ciais; Robert Clement; Bruce D. Cook; Peter S. Curtis; D. Bryan Dail; Ebba Dellwik; Nicolas Delpierre; Ankur R. Desai; Sabina Dore; Danilo Dragoni; Bert G. Drake; Eric Dufrêne; Allison Dunn; Jan Elbers; Werner Eugster; Matthias Falk; Christian Feigenwinter; Lawrence B. Flanagan; Thomas Foken; John Frank; Juerg Fuhrer; Damiano Gianelle; Allen Goldstein; Mike Goulden; Andre Granier; Thomas Grünwald; Lianhong Gu; Haiqiang Guo; Albin Hammerle; Shijie Han; Niall P. Hanan; László Haszpra; Bernard Heinesch; Carole Helfter; Dimmie Hendriks; Lindsay B. Hutley; Andreas Ibrom; Cor Jacobs; Torbjörn Johansson; Marjan Jongen; Gabriel Katul; Gerard Kiely; Katja Klumpp; Alexander Knohl; Thomas Kolb; Werner L. Kutsch; Peter Lafleur; Tuomas Laurila; Ray Leuning; Anders Lindroth; Heping Liu; Benjamin Loubet; Giovanni Manca; Michal Marek; Hank A. Margolis; Timothy A. Martin; William J. Massman; Roser Matamala; Giorgio Matteucci; Harry McCaughey; Lutz Merbold; Tilden Meyers; Mirco Migliavacca; Franco Miglietta; Laurent Misson; Meelis Mölder; John Moncrieff; Russell K Monson; Leonardo Montagnani; Mario Montes-Helu; Eddy Moors; Christine Moureaux; Mukufute M Mukelabai; J William Munger; May Myklebust; Zoltán Nagy; Asko Noormets; Walter Oechel; Ram Oren; Stephen G Pallardy; Kyaw Tha Paw U; João S Pereira; Kim Pilegaard; Krisztina Pintér; Casimiro Pio; Gabriel Pita; Thomas L Powell; Serge Rambal; James T Randerson; Corinna Rebmann; Janne Rinne; Federica Rossi; Nigel Roulet; Ronald J Ryel; Jorgen Sagerfors; Nobuko Saigusa; María José Sanz; Giuseppe-Scarascia Mugnozza; Hans Peter Schmid; Guenther Seufert; Mario Siqueira; Jean-François Soussana; Gregory Starr; Mark A Sutton; John Tenhunen; Juha-Pekka Tuovinen; Riccardo Valentini; Christoph S Vogel; Jingxin Wang; Shaoqiang Wang; Weiguo Wang; Lisa R Welp; Xuefa Wen; Sonia Wharton; Matthew Wilkinson; Christopher A Williams; Georg Wohlfahrt; Susumu Yamamoto; Guirui Yu; Roberto Zampedri; Bin Zhao; Xinquan Zhao

2010-01-01

347

Terrestrial Carbon Cycle Feedback to Climate Warming: Experimental Evidence  

Microsoft Academic Search

Global climate modeling has demonstrated that climate warming would stimulate respiratory CO2 release from the terrestrial ecosystems to the atmosphere, which in turn leads to more warming in the climate system. This positive feedback between the climate change and the terrestrial carbon cycle can form a vicious cycle that potentially leads to a dangerous threat to ecosystem functioning and service.

Y. Luo; X. Zhou; R. Sherry

2006-01-01

348

Simulated space flight testing of commercial terrestrial silicon cells  

Microsoft Academic Search

Low cost silicon solar cells manufactured for the terrestrial market are examined for possible space flight use. The results of preliminary space environmental testing are reported and discussed. In addition, a number of possible obstacles to the use of these cells is examined. It is concluded that the terrestrial industry could provide an extremely low cost and reliable cell for

P. M. Stella; T. F. Miyahira

1982-01-01

349

Terrestrial Vegetation of the United States: Volume 1  

NSDL National Science Digital Library

The NatureServe (formerly The Nature Conservancy) has posted this publication on their Website. NatureServe offers the publication Terrestrial Vegetation of the United States in two volumes -- representing "the first standardized classification of the terrestrial ecological communities of the United States ever developed at a scale fine enough to be used in making local, site-specific conservation decisions."

350

DOES TERRESTRIAL CARBON SUBSIDIZE PRODUCTION OF ESTUARINE FISH LARVAE?  

EPA Science Inventory

The research presented demonstrates the important role that terrestrial ecosystems can play in coastal food webs. We show that terrestrial carbon subsidizes the tidal freshwater and oligohaline portions of an estuarine food web, but that this exogenous carbon source is not impor...

351

The role of terrestriality in promoting primate technology.  

PubMed

"Complex technology" has often been considered a hallmark of human evolution. However, recent findings show that wild monkeys are also capable of habitual tool use. Here we suggest that terrestriality may have been of crucial importance for the innovation, acquisition, and maintenance of "complex" technological skills in primates. Here we define complex technological skills as tool-use variants that include at least two tool elements (for example, hammer and anvil), flexibility in manufacture or use (that is, tool properties are adjusted to the task at hand), and that skills are acquired in part by social learning. Four lines of evidence provide support for the terrestriality effect. First, the only monkey populations exhibiting habitual tool use seem to be particularly terrestrial. Second, semi-terrestrial chimpanzees have more complex tool variants in their repertoire than does their arboreal Asian relative, the orangutan. Third, tool variants of chimpanzees used in a terrestrial setting tend to be more complex than those used exclusively in arboreal contexts. Fourth, the higher frequency in tool use among captive versus wild primates of the same species may be attributed in part to a terrestriality effect. We conclude that whereas extractive foraging, intelligence, and social tolerance are necessary for the emergence of habitual tool use, terrestriality seems to be crucial for acquiring and maintaining complex tool variants, particularly expressions of cumulative technology, within a population. Hence, comparative evidence among primates supports the hypothesis that the terrestriality premium may have been a major pacemaker of hominin technological evolution. PMID:22499440

Meulman, Ellen J M; Sanz, Crickette M; Visalberghi, Elisabetta; van Schaik, Carel P

2012-03-01

352

Terrestrial background reduction in RPM systems by direct internal shielding  

Microsoft Academic Search

Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of radiation portal monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. This issue will become even more important as the next generation of spectroscopic-capable

Sean M. Robinson; Eric D. Ashbaker; John E. Schweppe

2008-01-01

353

Communicating with Children.  

ERIC Educational Resources Information Center

|Effective communication with children is a human process that can help or hinder development. The term "communication" encompasses both the content perspective (what is communicated) and the transportation perspective (the manner in which meaning is communicated). The most important communication factor, human perspective, has two implications…

Knoepfli, Heather E.

354

Defining Strategic Communication  

Microsoft Academic Search

This article examines the nature of strategic communication, which is defined as the purposeful use of communication by an organization to fulfill its mission. Six relevant disciplines are involved in the development, implementation, and assessment of communications by organizations: management, marketing, public relations, technical communication, political communication, and information\\/social marketing campaigns. The nature of the term strategic is examined, and

Kirk Hallahan; Derina Holtzhausen; Betteke van Ruler; Dejan Ver?i?; Krishnamurthy Sriramesh

2007-01-01

355

Communicating with Villagers.  

ERIC Educational Resources Information Center

Common problems and possible solutions in communication with rural villagers in developing countries are discussed in terms of communication extension strategies, mass communication media, the use of simple communication technology in place of the more sophisticated and expensive methods, a case study of a successful communication project in…

Colle, Royal D.

356

Terrestrial Planet Finder: technology development plans  

NASA Astrophysics Data System (ADS)

One of humanity's oldest questions is whether life exists elsewhere in the universe. The Terrestrial Planet Finder (TPF) mission will survey stars in our stellar neighborhood to search for planets and perform spectroscopic measurements to identify potential biomarkers in their atmospheres. In response to the recently published President's Plan for Space Exploration, TPF has plans to launch a visible-light coronagraph in 2014, and a separated-spacecraft infrared interferometer in 2016. Substantial funding has been committed to the development of the key technologies that are required to meet these goals for launch in the next decade. Efforts underway through industry and university contracts and at JPL include a number of system and subsystem testbeds, as well as components and numerical modeling capabilities. The science, technology, and design efforts are closely coupled to ensure that requirements and capabilities will be consistent and meet the science goals.

Lindensmith, Christian A.

2004-10-01

357

Terrestrial refraction and vertical temperature gradient  

NASA Astrophysics Data System (ADS)

An assessment of the techniques and accuracy of current observations of coefficient of terrestrial refraction, including its diurnal and seasonal variations, is presented. One methodology has employed 1924 measurements of vertical angles between two geodetic stations with either one-way or line refraction techniques. The stations were 15 km apart and at heights of 177 and 361 m. Additional data has been gathered from adjustments of trigonometric leveling traverses with vertical angle capability, using stations 4 km apart. Another network featured lines of 4-23 km, with measurements repeated 12-60 hours sequentially. Mention is also given to measuring light attenuation and evaluation of the vertical refraction angle from the variance of the angle of arrival fluctuations. Formulas for modeling the vertical temperature gradient are discussed.

Mavridis, L. N.

358

Terrestrial interface architecture (DSI/DNI)  

NASA Astrophysics Data System (ADS)

The 64-kbit/s digital speech interpolation (DSI)/digital noninterpolation (DNI) equipment interfaces the TDMA satellite system with the terrestrial network. This paper provides a functional description of the 64-kbit/s DSI/DNI equipment built at Comsat Laboratories in conformance with the Intelsat TDMA/DSI system specification, and discusses the theoretical and experimental performance of the DSI system. Several DSI-related network and interface issues are discussed, including the interaction between echo-control devices and DSI speech detectors, single and multidestinational DSI operation, location of the DSI equipment relative to the international switching center, and the location and need for Doppler and plesiochronous alignment buffers. The transition from 64-kbit/s DSI to 32-kbit/s low-rate encoding/DSI is expected to begin in 1988. The impact of this transition is discussed as it relates to existing 64-kbit/s DSI/DNI equipment.

Rieser, J. H.; Onufry, M.

359

The origin of modern terrestrial life  

PubMed Central

The study of the origin of life covers many areas of expertise and requires the input of various scientific communities. In recent years, this research field has often been viewed as part of a broader agenda under the name of “exobiology” or “astrobiology.” In this review, we have somewhat narrowed this agenda, focusing on the origin of modern terrestrial life. The adjective “modern” here means that we did not speculate on different forms of life that could have possibly appeared on our planet, but instead focus on the existing forms (cells and viruses). We try to briefly present the state of the art about alternative hypotheses discussing not only the origin of life per se, but also how life evolved to produce the modern biosphere through a succession of steps that we would like to characterize as much as possible.

Forterre, Patrick; Gribaldo, Simonetta

2007-01-01

360

Solar-terrestrial news from NSF  

NASA Astrophysics Data System (ADS)

This is a difficult time for solar-terrestrial (S/T) research. The loss of the shuttle Challenger has disrupted the entire short-range launch schedule at the National Aeronautics and Space Administration (NASA). The Gramm-Rudman-Hollings (GRH) Deficit Reduction Act has affected virtually all programs in fiscal year (FY) 1986 and no doubt will affect 1987 and beyond. Then again, every year has its own special problems, and even this year's difficulties could turn to our advantage. For example, GRH has demanded a serious rethinking of budgets and priorities. One outcome of this is the President's budget to Congress in 1987, which requests increases of 8.4% and 8.9% for the National Science Foundation (NSF) and NASA (research and development), respectively.

Peacock, Dennis

361

Moon and Terrestrial Planets: Unresolved Questions  

NASA Astrophysics Data System (ADS)

Human exploration during Apollo began the documentation of the evolution of the Moon and of its importance in understanding the origin and evolution of the terrestrial planets. This revolution in planetary geology continues as a vigorous and vibrant arena for discovery and debate for new generations of geoscientists. Although much has been learned and, indeed, resolved in lunar science, we are left with major questions unresolved. One fundamental question is that of the origin of the Moon. A large consensus has developed in the planetary science community that the Moon was created by the "giant impact" of a Mars-sized asteroid on the Earth after the accretion of the Earth was largely complete and differentiation had begun. A minority, however, questions this consensus hypothesis because of increasing indications that the lower mantle of the Moon may be largely undifferentiated. If the issue of the high angular momentum of the Earth-Moon system can be resolved through new modeling studies, then capture of a co-orbiting planetesimal may be an important alternative to a "giant impact". Another important question, particularly in consideration of the terrestrial and Martian surface environments during the first 0.8 billion years of Earth history, is the impact record of that period as recorded on the Moon. Again, a large consensus has developed that the 50 or so large and very large impact basins identified on the Moon were created over a very short "cataclysm" between about 3.9 and 3.8 billion years ago. Here also, a minority suggests that this period of large basin formation, although distinct in lunar history, took place over several hundred million years and that the apparent cataclysm is an artifact of sampling the effects of the last few basin-forming impacts. Either way, a previously unavailable source of impactors appeared somewhere in the solar system and greatly affected terrestrial environments at the time the precursors to life were appearing on Earth. Additional unresolved questions raised by lunar exploration and study include 1) the effect of chondritic proto-cores on the timing of core formation in the terrestrial planets, 2) the number of extremely large basin-forming events (lunar diameters >2000 km) and the potential for proto-continents being formed by the differentiation of their melt sheets on water-rich planets, 3) effect of clays produced by the weathering of the debris and glass produced by pervasive asteroid and cometary impacts, 4) the many details of the differentiation of magma oceans, and 5) the processes governing the evolution of the lunar regolith. Finally, there is the question of when humans shall return to the Moon. On the one hand, the use of this unique and accessible planetary body as a scientific resource has barely begun. On the other hand, the Helium-3 fusion energy resources and deep space travel consumables that remain untapped in the lunar regolith hardly can be ignored in the face of human and environmental challenges on Earth and the species' desire to go to Mars. On both hands, it is time we took another walk on the Moon. 30 years going on 40 is long enough to think about what once was possible.

Schmitt, H. H.

2002-12-01

362

Solar terrestrial coupling through space plasma processes  

SciTech Connect

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations.

Birn, J. [and others

2000-12-01

363

Circumstellar habitable zones for deep terrestrial biospheres  

NASA Astrophysics Data System (ADS)

The habitable zone (HZ) is conventionally the thin shell of space around a star within which liquid water is thermally stable on the surface of an Earth-like planet (Kasting et al., 1993). However, life on Earth is not restricted to the surface and includes a "deep biosphere" reaching several km in depth. Similarly, subsurface liquid water maintained by internal planetary heat could potentially support life well outside conventional HZs. We introduce a new term,subsurface-habitability zone (SSHZ) to denote the range of distances from a star within which rocky planets are habitable at any depth below their surfaces up to a stipulated maximum, and show how SSHZs can be estimated from a model relating temperature, depth and orbital distance. We present results for Earth-like, Mars-like and selected extrasolar terrestrial planets, and conclude that SSHZs are several times wider and include many more planets than conventional surface-based habitable zones.

McMahon, Sean; O'Malley-James, Jack; Parnell, John

2013-09-01

364

Regional quasigeoid from GOCE and terrestrial measurements  

NASA Astrophysics Data System (ADS)

The contribution presents our first results obtained as a solution of geodetic boundary-value problem where two different sources of input boundary data are combined together. On the upper part of the boundary, separated from the Earth masses, the gravity anomalies are derived from GOCE gravity gradiometry data using a transformation and downward continuation procedure. On the bottom part of the boundary, created by the Earth surface, the gravity anomalies are prepared from the terrestrial or marine gravity measurements. The boundary-value problem is then solved numerically by either parallel Finite Volume or Finite Element Methods. Advantage of this combined numerical approach is high resolution, homogenity and independency from the high-degree global gravity models.

Janák, Juraj; Pito?ák, Martin; Minarechová, Zuzana

2013-04-01

365

The role of flares for terrestrial planets  

NASA Astrophysics Data System (ADS)

Flares, especially giant ones affect the atmospheres of terrestrial planets. In order to better understand the processes involved we have initiated a study of flares in the CoRoT-database. In our survey we have detected several active stars with flares. These show the usual behaviour: a rapid increase followed by a slow decay. The obtained cumulative frequency diagram follows a power law. In addition to these flares we found 50 huge flare-like events on otherwise inactive stars. In contrast to the flares which have blue colours these events show a mixture of different colours and shapes. They thus resemble the events on a sample of solar-like stars first noticed by Schaefer et al. more than 10 years ago.

Drabent, A.; Guenther, E. W.

2011-10-01

366

Planet Formation: Terrestrial and Extra Solar  

NASA Astrophysics Data System (ADS)

The Conference on Planet Formation: Terrestrial and Extra Solar was held near the end of a three month workshop of the same name. The purpose of the conference was to discuss topics in planet formation, evolution, and detection. The recent discoveries of extrasolar planets(now numbering around 100), combined with recently obtained observational upper limits on the lifetimes of protoplanetary disks, make this an ideal time to rethink how planets form. This program will examine the formation process from dust grains to planetesimals, from planetesimals to Earth mass bodies or multiple-Earth mass cores, and from cores to gas giant planets. It will also consider post-formation evolution, e.g., planet-disk interactions, in an attempt to understand both the very short orbital periods of many of the extrasolar planets, and their often large eccentricities.

Lin, Douglas N. C.; Lunine, Jonathan; Murray, Norman

2004-03-01

367

Constructing a database of terrestrial radiocarbon measurements  

NASA Astrophysics Data System (ADS)

Terrestrial Radiocarbon Database Workshop; Berkeley, California, 20-22 July 2011 Soils play a large role in the global carbon (C) cycle, but soil C stocks and dynamics remain highly uncertain. Radiocarbon (14C) observations provide critical information on the rates of exchange of soil C with the atmosphere and hydrosphere and how those rates vary with edaphic (soil-related) factors and over a range of time scales. For example, the degree to which radio decay has affected 14C demonstrates the importance of short-range-order minerals for stabilizing organic C on millennial time scales in some soils. Time series that track the infiltration of “bomb” 14C help identify the components of soil C that cycle on decadal to centennial time scales.

Trumbore, Susan; Torn, Margaret; Smith, Lydia

2011-10-01

368

15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false National Geophysical and Solar-Terrestrial Data Center (NGSDC... § 950.5 National Geophysical and Solar-Terrestrial Data Center (NGSDC). The National Geophysical and Solar-Terrestrial Data Center...

2010-01-01

369

15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false National Geophysical and Solar-Terrestrial Data Center (NGSDC... § 950.5 National Geophysical and Solar-Terrestrial Data Center (NGSDC). The National Geophysical and Solar-Terrestrial Data Center...

2009-01-01

370

Primate communication in the pure ultrasound  

PubMed Central

Few mammals—cetaceans, domestic cats and select bats and rodents—can send and receive vocal signals contained within the ultrasonic domain, or pure ultrasound (greater than 20 kHz). Here, we use the auditory brainstem response (ABR) method to demonstrate that a species of nocturnal primate, the Philippine tarsier (Tarsius syrichta), has a high-frequency limit of auditory sensitivity of ca 91 kHz. We also recorded a vocalization with a dominant frequency of 70 kHz. Such values are among the highest recorded for any terrestrial mammal, and a relatively extreme example of ultrasonic communication. For Philippine tarsiers, ultrasonic vocalizations might represent a private channel of communication that subverts detection by predators, prey and competitors, enhances energetic efficiency, or improves detection against low-frequency background noise.

Ramsier, Marissa A.; Cunningham, Andrew J.; Moritz, Gillian L.; Finneran, James J.; Williams, Cathy V.; Ong, Perry S.; Gursky-Doyen, Sharon L.; Dominy, Nathaniel J.

2012-01-01

371

Intermittent Astrophysical Radiation Sources and Terrestrial Life  

NASA Astrophysics Data System (ADS)

Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

Melott, Adrian

2013-04-01

372

Mercury speciation analysis in terrestrial animal tissues.  

PubMed

No previous analytical procedures are available and validated for mercury speciation analysis in terrestrial animal tissues. This analysis is a difficult task both because the expected concentrations are low, since important accumulation process are not likely to occur, and also because there are not commercially available certified reference material. Thus, an analytical methodology has been developed and validated for mercury speciation for the specific case of terrestrial animal tissues. The proposed method is based on the quantitative extraction of the species by closed-vessel microwave assisted heating with an alkaline reagent, followed by ethylation. The ethylated derivatives were then submitted to head-space solid phase microextraction with a 100 ?m polidimethylsiloxane-coated fiber, and desorbed onto a gas chromatograph coupled to atomic fluorescence detection via pyrolysis unit (HS-SPME-GC-pyro-AFS). Procedural detection limits were 31.8 ng g(-1) and 52.5 ng g(-1) for CH(3)Hg(+) and Hg(2+), respectively, for liver and 35.3 ng g(-1) and 58.1 ng g(-1) for CH(3)Hg(+) and Hg(2+), respectively, for kidney. These limits of detection are 5.5 and 6 times better than the obtained without solid phase microextraction for CH(3)Hg(+) and Hg(2+), respectively. The methodology was found linear up to 120 ?g L(-1) and reproducible from one day to the following. It was validated with certified reference materials NCS ZC 71001 (beef liver) and BCR No 186 (pig kidney) for total mercury, calculated as the sum of species, and with spiked red deer liver and kidney for speciation. Finally, it was applied to the analysis of samples of red deer liver, red deer kidney and wild boar kidney coming from the Almadén's mercury mining area (Ciudad Real, Spain), the longest and largest producer of mercury in the world until its closure in 2002. PMID:22967634

Berzas Nevado, J J; Rodríguez Martín-Doimeadios, R C; Guzmán Bernardo, F J; Rodríguez Fariñas, N; Patiño Ropero, M J

2012-07-24

373

Future hotspots of terrestrial mammal loss  

PubMed Central

Current levels of endangerment and historical trends of species and habitats are the main criteria used to direct conservation efforts globally. Estimates of future declines, which might indicate different priorities than past declines, have been limited by the lack of appropriate data and models. Given that much of conservation is about anticipating and responding to future threats, our inability to look forward at a global scale has been a major constraint on effective action. Here, we assess the geography and extent of projected future changes in suitable habitat for terrestrial mammals within their present ranges. We used a global earth-system model, IMAGE, coupled with fine-scale habitat suitability models and parametrized according to four global scenarios of human development. We identified the most affected countries by 2050 for each scenario, assuming that no additional conservation actions other than those described in the scenarios take place. We found that, with some exceptions, most of the countries with the largest predicted losses of suitable habitat for mammals are in Africa and the Americas. African and North American countries were also predicted to host the most species with large proportional global declines. Most of the countries we identified as future hotspots of terrestrial mammal loss have little or no overlap with the present global conservation priorities, thus confirming the need for forward-looking analyses in conservation priority setting. The expected growth in human populations and consumption in hotspots of future mammal loss mean that local conservation actions such as protected areas might not be sufficient to mitigate losses. Other policies, directed towards the root causes of biodiversity loss, are required, both in Africa and other parts of the world.

Visconti, Piero; Pressey, Robert L.; Giorgini, Daniele; Maiorano, Luigi; Bakkenes, Michel; Boitani, Luigi; Alkemade, Rob; Falcucci, Alessandra; Chiozza, Federica; Rondinini, Carlo

2011-01-01

374

Evaluating Terrestrial Carbon Sequestration Options for Virginia  

NASA Astrophysics Data System (ADS)

Changes in forest and agricultural land management practices have the potential to increase carbon (C) storage by terrestrial systems, thus offsetting C emissions to the atmosphere from energy production. This study assesses that potential for three terrestrial management practices within the state of Virginia, USA: afforestation of marginal agricultural lands; afforestation of riparian agricultural lands; and changing tillage practices for row crops; each was evaluated on a statewide basis and for seven regions within the state. Lands eligible for each practice were identified, and the C storage potential of each practice on those lands was estimated through a modeling procedure that utilized land-resource characteristics represented in Geographic Information System databases. Marginal agricultural lands’ afforestation was found to have the greatest potential (1.4 Tg C yr-1, on average, over the first 20 years) if applied on all eligible lands, followed by riparian afforestation (0.2 Tg C yr-1 over 20 years) and tillage conversion (0.1 Tg C yr-1 over 14 years). The regions with the largest potentials are the Ridge and Valley of western Virginia (due to extensive areas of steep, shallow soils) and in the Mid-Atlantic Coastal Plain in eastern Virginia (wet soils). Although widespread and rapid implementation of the three modeled practices could be expected to offset only about 3.4% of Virginia’s energy-related CO2 emissions over the following 20 years (equivalent to about 8.5% of a Kyoto Treaty-based target), they could contribute to achievement of C-management goals if implemented along with other mitigation measures.

Galang, Jeffrey S.; Zipper, Carl E.; Prisley, Stephen P.; Galbraith, John M.; Donovan, Patricia F.

2007-02-01

375

Terrestrial hydrological Research and Geophysics: Quo Vadis?  

NASA Astrophysics Data System (ADS)

Geophysical methods may play an important role in managing our terrestrial environment and in maintaining ecosystem functioning and services. Especially, the application and further development of hydrogeophysical methods seem very promising to maintain and protect soil and groundwater quality. Hydrogeophysical methods may help to improve our control on storage, filter and buffer functions of soils and groundwater systems. Moreover, methods are needed that will help us to bridge the gap between the scale of measurements and observations and the scale at which management of terrestrial systems takes place. In this presentation several examples will be presented showing how hydrogeophysical research can contribute in meeting these challenges. Recent progress in the field of magnetic resonance imaging, electrical resistivity tomography and spectral induced polarisation to investigate flow and transport processes in soils will be presented. In the field of high frequency hydrogeophysics, advanced full-waveform forward and inverse modelling procedures have been developed for ground penetrating radar technology, which are now routinely used for high-resolution, real-time mapping of surface soil moisture at the field scale. Integrated inversion and data fusion strategies, where both geophysical and hydrological models are coupled, further extend information retrieval capabilities also in real-time, and permits advanced interpretation of time-lapse data for hydrological process identification, water dynamics monitoring and soil hydraulic properties determination. Advances in wireless and sensor technologies are increasing the feasibility of using distributed sensor networks for observing soil water and hydrological processes at the intermediate scale, bridging the gap between ground-based sensors and remote sensing platforms.

Vereecken, H.; Huisman, J. A.; van der Kruk, J.; Bogena, H.; Pohlmeier, A.; Koestel, J.; Lambot, S.; Vanderborght, J.

2009-04-01

376

A soluble calcium-binding protein from the terrestrial annelid Lumbricus terrestris L  

Microsoft Academic Search

Soluble calcium-binding proteins (SCBP) considerably different from calmodulin were purified from the body wall muscle of the earthwormLumbricus terrestris. Three isoforms were obtained with similar UV absorption spectra and amino acid compositions and an apparent molecular weight close to 20 kDa. They can be distinguished by their histidine and proline content and by their peptide maps. The tissue content, as

R. Huch; J. D'Haese; Ch. Gerday

1988-01-01

377

Impact of a perfluorinated organic compound PFOS on the terrestrial pollinator Bombus terrestris (Insecta, Hymenoptera)  

Microsoft Academic Search

Perfluorinated organic chemicals like perfluorooctane sulfonic acid (PFOS) are persistent environmental pollutants that have\\u000a been measured in a great diversity of wildlife worldwide, especially in the aquatic compartment. However, little information\\u000a is available on the presence and effects of PFOS in the terrestrial compartment. Therefore, we investigated in this project\\u000a the risks for effects, bioaccumulation and potential mechanisms of activity

Veerle Mommaerts; An Hagenaars; Johan Meyer; Wim De Coen; Luc Swevers; Hadi Mosallanejad; Guy Smagghe

2011-01-01

378

Effective Communication Effective Communication about Risk ...  

Center for Biologics Evaluation and Research (CBER)

Text Version... Page 11. ? Communication in pharmacies Communication in pharmacies Page 12. Svarstad et al. ... Stringency: 1 if face-to-face counseling must be ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

379

Delay-Insensitive Communication.  

National Technical Information Service (NTIS)

Communication is called delay insensitive if it is delay safe and it has absence of transmission interference hazard. The communication model proposed is introduced. The communication model provides a clear separation between the interpretation of physica...

H. M. J. Schols

1992-01-01

380

Interpersonal Communications Workshop.  

National Technical Information Service (NTIS)

The major purpose of an interpersonal communications workshop is to provide participants the opportunity to acquire knowledge and practice skills in face-to-face communication, individual communicating style, group and organizational factors which affect ...

S. Buel C. Hosford

1972-01-01

381

Communication for Child Survival,  

National Technical Information Service (NTIS)

The manual presents a systematic public health communication methodology for child survival programs. It is meant for health and communication professionals who wish to use communication strategies to improve child health in the developing world. The manu...

M. R. Rasmuson R. E. Seidel W. A. Smith E. M. Booth

1988-01-01

382

ADS Communications: A Cornerstone.  

National Technical Information Service (NTIS)

ADS Communications forms a cornerstone to the applications and communications networks of the 21st century. The need to communicate operational data between an aircraft and the Air Traffic Services is becoming focused and will lead to ever increasing appl...

G. A. Cobley

1991-01-01

383

Promoting active communication behaviours through internal communication  

Microsoft Academic Search

Purpose – The purpose of this paper is to propose a definition of internal communication based on intangible resources rather than organizational boundaries. Design\\/methodology\\/approach – The paper reviews the resource-based theory of the company, the constructivist theory of communication and the situational theory of publics. It then proposes a resource model (RM) of internal communication based on interactive processes aimed

Alessandra Mazzei

2010-01-01

384

A new phase for NASA's communications satellite program  

NASA Astrophysics Data System (ADS)

NASA's research in communications satellite technology is discussed, including orbit-efficient techniques and applications by the commercial sector. Attention is given to expanding the capacities of the C-band (6-4 GHz) and the Ku-band (14-11 GHz), opening the Ka-band (30/20 GHz), broadly applied 're-use' of the spectrum, and developing multibeam spacecraft antennas with on-board switching. Increasing wideband services in video, high-speed data, and voice trunking is considered, as are narrow-band systems that may be used for data collection or public safety, with possible expansion to a thin-route satellite system. In particular, communication for medical, disaster, or search-and-rescue emergencies may be met by the integration of a satellite service with land mobile communications via terrestrial radio links. Also considered is a large geostationary platform providing electrical power, thermal rejection, and orbital station-keeping for many communications payloads.

Dement, D. K.

1980-01-01

385

Section 8100: Communication  

Center for Biologics Evaluation and Research (CBER)

... Section 8200: Investigational New Drugs (INDs); Section 8400 ... Section 8100: Communication. ... of Email for Regulatory Communications Effective Date ... More results from www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/proceduressopps

386

VHDL modeling of PHY and MAC Layer modules for underwater optical wireless communication  

Microsoft Academic Search

In this paper the description of hardware modules for managing underwater wireless optical communication is proposed. The modules have been developed for testing purposes considering previous released protocols for optical wireless communication (i.e. IEEE 802.11-IR) and the characteristics of underwater medium and taking into account the possible integration with current technologies for terrestrial Wireless Sensor Network (WSNs). The here proposed

Davide Anguita; Davide Brizzolara; Giancarlo Parodi

2010-01-01

387

THE COMPOSITIONAL DIVERSITY OF EXTRASOLAR TERRESTRIAL PLANETS. II. MIGRATION SIMULATIONS  

SciTech Connect

Prior work has found that a variety of terrestrial planetary compositions are expected to occur within known extrasolar planetary systems. However, such studies ignored the effects of giant planet migration, which is thought to be very common in extrasolar systems. Here we present calculations of the compositions of terrestrial planets that formed in dynamical simulations incorporating varying degrees of giant planet migration. We used chemical equilibrium models of the solid material present in the disks of five known planetary host stars: the Sun, GJ 777, HD4203, HD19994, and HD213240. Giant planet migration has a strong effect on the compositions of simulated terrestrial planets as the migration results in large-scale mixing between terrestrial planet building blocks that condensed at a range of temperatures. This mixing acts to (1) increase the typical abundance of Mg-rich silicates in the terrestrial planets' feeding zones and thus increase the frequency of planets with Earth-like compositions compared with simulations with static giant planet orbits, and (2) drastically increase the efficiency of the delivery of hydrous phases (water and serpentine) to terrestrial planets and thus produce waterworlds and/or wet Earths. Our results demonstrate that although a wide variety of terrestrial planet compositions can still be produced, planets with Earth-like compositions should be common within extrasolar planetary systems.

Carter-Bond, Jade C. [School of Physics, University of New South Wales, Kensington, NSW 2052 (Australia); O'Brien, David P. [Planetary Science Institute, 1700 East Fort Lowell, Tucson, AZ 85719 (United States); Raymond, Sean N., E-mail: j.bond@unsw.edu.au [Observatoire Aquitain des Sciences de l'Univers, Universite de Bordeaux, 2 rue de l'Observatoire, BP 89, F-33271 Floirac Cedex (France)

2012-11-20

388

Reproductive mode plasticity: Aquatic and terrestrial oviposition in a treefrog  

PubMed Central

Diversification of reproductive mode is a major theme in animal evolution. Vertebrate reproduction began in water, and terrestrial eggs evolved multiple times in fishes and amphibians and in the amniote ancestor. Because oxygen uptake from water conflicts with water retention in air, egg adaptations to one environment typically preclude development in the other. Few animals have variable reproductive modes, and no vertebrates are known to lay eggs both in water and on land. We report phenotypic plasticity of reproduction with aquatic and terrestrial egg deposition by a frog. The treefrog Dendropsophus ebraccatus, known to lay eggs terrestrially, also lays eggs in water, both at the surface and fully submerged, and chooses its reproductive mode based on the shade above a pond. Under unshaded conditions, in a disturbed habitat and in experimental mesocosms, these frogs lay most of their egg masses aquatically. The same pairs also can lay eggs terrestrially, on vegetation over water, even during a single night. Eggs can survive in both aquatic and terrestrial environments, and variable mortality risks in each may make oviposition plasticity adaptive. Phylogenetically, D. ebraccatus branches from the basal node in a clade of terrestrially breeding species, nested within a larger lineage of aquatic-breeding frogs. Reproductive plasticity in D. ebraccatus may represent a retained ancestral state intermediate in the evolution of terrestrial reproduction.

Touchon, Justin Charles; Warkentin, Karen Michelle

2008-01-01

389

Estimating Exposure of Terrestrial Wildlife to Contaminants  

SciTech Connect

This report presents a general model for exposure of terrestrial wildlife to contaminants (Sect. 2), methods for estimating parameters of the model (Sect. 3), species specific parameters for endpoint species on the Oak Ridge Reservation (ORR) (Sect. 4), and a sample application (Sect. 5). Exposure can be defined as the coincidence in both space and time of a receptor and a stressor, such that the receptor and stressor come into contact and interact (Risk Assessment Forum 1992). In the context of ecological risk assessment, receptors include all endpoint species or communities identified for a site [see Suter (1989) and Suter et al. (1994) for discussions of ecological endpoints for waste sites]. In the context of waste site assessments, stressors are chemical contaminations, and the contact and interaction are uptake of the contaminant by the receptor. Without sufficient exposure of the receptor to the contaminants, there is no ecological risk. Unlike some other endpoint assemblages, terrestrial wildlife are significantly exposed to contaminants in multiple media. They may drink or swim in contaminated water, ingest contaminated food and soil, and breath contaminated air. In addition, because most wildlife are mobile, moving among and within habitats, exposure is not restricted to a single location. They may integrate contamination from several spatially discrete sources. Therefore, exposure models for terrestrial wildlife must include multiple media. This document provides models and parameters for estimating exposure of birds and mammals. Reptiles and amphibians are not considered because few data exist with which to assess exposure to these organisms. In addition, because toxicological data are scarce for both classes, evaluation of the significance of exposure estimates is problematic. However, the general exposure estimation procedure developed herein for birds and mammals is applicable to reptiles and amphibians. Exposure models must be appropriate to the assessment endpoints. The models presented herein are models of the exposure of individual organisms, but except for threatened and endangered species, all the wildlife endpoints for the ORR are for populations (Suter et al. 1994). The use of organism exposures is appropriate because of the need to integrate exposure estimates with exposure-response information which is expressed as organism-level responses. The conversion of individual exposure to population effects occurs in the risk characterization. Conceptually, the conversion of organism-level exposures to the population level can be made in two ways. First, it may be assumed that there is a distinct population on the site so that the exposure of the population is the exposure of all the individuals. This assumption is appropriate for small organisms on large sites, particularly if the site constitutes a distinct habitat that is surrounded by inappropriate habitat. For example, a grassy site surrounded by forest or industrial development might support a distinct population of voles. The risks to that population can be estimated directly from the exposures of the individual organisms. Second, it may be assumed that a certain number of individuals are exposed to contaminants out of a larger population. For example, a certain proportion of a deer herd may forage on a site or a pair of hawks may hunt on a site. The estimated exposure of these individuals will result in estimation of certain effects on those individuals, and the resulting population risks will need to be characterized. In either case, the organism level exposure models are appropriate.

Sample, B.E.

1994-01-01

390

Terrestrial nitrogen-carbon cycle interactions at the global scale.  

PubMed

Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing. PMID:23713123

Zaehle, S

2013-05-27

391

Terrestrial Ecosystems of the Conterminous United States  

USGS Publications Warehouse

The U.S. Geological Survey (USGS), with support from NatureServe, has modeled the potential distribution of 419 terrestrial ecosystems for the conterminous United States using a comprehensive biophysical stratification approach that identifies distinct biophysical environments and associates them with known vegetation distributions (Sayre and others, 2009). This standardized ecosystem mapping effort used an ecosystems classification developed by NatureServe (Comer and others, 2003). The ecosystem mapping methodology was developed for South America (Sayre and others, 2008) and is now being implemented globally (Sayre and others, 2007). The biophysical stratification approach is based on mapping the major structural components of ecosystems (land surface forms, topographic moisture potential, surficial lithology, isobioclimates and biogeographic regions) and then spatially combining them to produce a set of unique biophysical environments. These physically distinct areas are considered as the fundamental structural units ('building blocks') of ecosystems, and are subsequently aggregated and labeled using the NatureServe classification. The structural footprints were developed from the geospatial union of several base layers including biogeographic regions, isobioclimates (Cress and others, 2009a), land surface forms (Cress and others, 2009b), topographic moisture potential (Cress and others, 2009c), and surficial lithology (Cress and others, in press). Among the 49,168 unique structural footprint classes that resulted from the union, 13,482 classes met a minimum pixel count threshold (20,000 pixels) and were aggregated into 419 NatureServe ecosystems using a semiautomated labeling process based on rule-set formulations for attribution of each ecosystem. The resulting ecosystems are those that are expected to occur based on the combination of the bioclimate, biogeography, and geomorphology. Where land use by humans has not altered land cover, natural vegetation assemblages are expected to occur, and these are described in the ecosystems classification. The map does not show the distribution of urban and agricultural areas - these will be masked out in subsequent analyses to depict the current land cover in addition to the potential distribution of natural ecosystems. This map depicts the smoothed and generalized image of the terrestrial ecosystems dataset. Additional information about this map and any data developed for the ecosystems modeling of the conterminous United States is available online at: http://rmgsc.cr.usgs.gov/ecosystems/.

Sayre, Roger; Comer, Patrick; Cress, Jill; Warner, Harumi

2010-01-01

392

A native IP satellite communications system  

NASA Astrophysics Data System (ADS)

? In the framework of ESA's ARTES-5 program the Institute of Applied Systems Technology (Joanneum Research) in cooperation with the Department of Communications and Wave Propagation has developed a novel meshed satellite communications system which is optimised for Internet traffic and applications (L*IP—Local Network Interconnection via Satellite Systems Using the IP Protocol Suite). Both symmetrical and asymmetrical connections are supported. Bandwidth on demand and guaranteed quality of service are key features of the system. A novel multi-frequency TDMA access scheme utilises efficient methods of IP encapsulation. In contrast to other solutions it avoids legacy transport network techniques. While the DVB-RCS standard is based on ATM or MPEG transport cells, the solution of the L*IP system uses variable-length cells which reduces the overhead significantly. A flexible and programmable platform based on Linux machines was chosen to allow the easy implementation and adaptation to different standards. This offers the possibility to apply the system not only to satellite communications, but provides seamless integration with terrestrial fixed broadcast wireless access systems. The platform is also an ideal test-bed for a variety of interactive broadband communications systems. The paper describes the system architecture and the key features of the system.

Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner-Puschl, S.; Riedler, W.

2004-08-01

393

Terrestrial sources and distribution of atmospheric sulphur  

PubMed Central

The general circulation model ECHAM has been coupled to a chemistry and sulphur cycle model to study the impact of terrestrial, i.e. mostly anthropogenic sulphur dioxide (SO2), sources on global distributions of sulphur species in the atmosphere. We briefly address currently available source inventories. It appears that global estimates of natural emissions are associated with uncertainties up to a factor of 2, while anthropogenic emissions have uncertainty ranges of about +/- 30 per cent. Further, some recent improvements in the model descriptions of multiphase chemistry and deposition processes are presented. Dry deposition is modelled consistently with meteorological processes and surface properties. The results indicate that surface removal of SO2 is less efficient than previously assumed, and that the SO2 lifetime is thus longer. Coupling of the photochemistry and sulphur chemistry schemes in the model improves the treatment of multiphase processes such as oxidant (hydrogen peroxide) supply in aqueous phase SO2 oxidation. The results suggest that SO2 oxidation by ozone (O3) in the aqueous phase is more important than indicated in earlier work. However, it appears that we still overestimate atmospheric SO2 concentrations near the surface in the relatively polluted Northern Hemisphere. On the other hand, we somewhat underestimate sulphate levels in these regions, which suggests that additional heterogeneous reaction mechanisms, e.g. on aerosols, enhance SO2 oxidation.

Lelieveld, J.; Roelofs, G.-J.; Ganzeveld, L.; Feichter, J.; Rodhe, H.

1997-01-01

394

International Solar-Terrestrial Physics Science Initiative  

NSDL National Science Digital Library

The National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Institute of Space and Astronautical Science (ISAS) of Japan have collaborated to make available the International Solar-Terrestrial Physics (ISTP) Science Initiative. The ISTP Science initiative has five primary objectives. For example, the initiative seeks to "determine structure and dynamics in the solar interior and their role in driving solar activity." Sections included at the Website are What is the Sun-Earth Connection, Mission Connection, and What's New. Furthermore, the What is the Sun-Earth Connection section is subdivided into sections such as What is Geospace (the space in between the Earth and the Sun), Studying the Invisible Realm, and Hot Pics and Cool Movies. Spectacular colorful images of Northern and Southern Lights from Earth and Space, Sun Spotting, Images of Earth from Space, Space Weather, and movies showing comets flying into the sun, solar eclipses, and solar tornadoes are presented in the Hot Pics and Cool Movies section.

1969-12-31

395

Nickel-hydrogen batteries for terrestrial applications  

NASA Astrophysics Data System (ADS)

Nickel-hydrogen battery technology is currently being adapted for terrestrial applications such as remote location power, utility load leveling, and the telecommunications industry. The battery is an inherently fault-tolerant design with excellent overcharge and overdischarge capabilities. The nickel-hydrogen battery is capable of extensive deep-cycling with no memory effect or cycle life degradation. The battery is contained within a hermetically sealed pressure vessel and operates at less than 200 psi. The system is truly maintenance-free. Battery state-of-charge is a direct linear function of the internal pressure, thereby allowing the condition of the battery to be instantly and accurately determined by a simple pressure gauge or transducer. It is concluded that projected costs per cycle are competitive with traditional lead-acid, nickel-cadmium, and nickel-iron batteries based on a useful life of twenty years. Projected life approaches forty years. Extensive testing is being done at both the cell and battery level with real-time life testing currently underway.

Coates, Dwaine; Roumpf, Galen; Baer, Steve

396

Terrestrial analog studies for Martian patterned ground  

NASA Astrophysics Data System (ADS)

A recurring problem in understanding Martian patterned ground is explaining its large size. Terrestrial patterned ground in Swedish Lapland offers an analog that may help explain this. In cold, arid regions with strong winds, polygonal features are accentuated paralled to the dominant wind direction. Preliminary results of a comparison between Martian polygonal troughs and dominant wind directions suggests a good correlation. This evolutionary model involving aeolian modification of Martian polygonal ground helps explain the large size features without requiring multiple, deep freeze-thaw cycles. A well-established geographical technique, nearest neighbor analysis, can be modified and applied to the distribution of patterned ground on Earth and Mars. The procedure determines the R-statistic, which reflects the degree to which on observation departs from an expected random pattern. The R-statistic is independent of scale, and therefore it can be applied to any size of type of pattern. Preliminary results indicate that there may be a correlation between the R-statistic and the process that create the polygons.

Rossbacher, L. A.

1985-04-01

397

SOTERIA: SOlar-TERrestrial Investigations and Archives  

NASA Astrophysics Data System (ADS)

The SOTERIA project realizes a wide synergy in the fields of solar- space- and geophysics to achieve a higher level of processed data and better understanding of solar and space events having terrestrial impact. The study of these events has an increasing importance with the increasing amount of technical equipment (e.g. power lines and telecommunication satellites) that can be damaged during these events. The project mobilizes more than 50 experts and significant resources from EU (including new EU member states) for the process, analysis, and interpretation of a large set of relevant data of more than 20 satellites (including 5 ESA missions) and the complementing ground-based data. It aims at providing better data bases and new methods to access and analyze them. The new databases go beyond the present state-of-the-art in details, and their on-line publication facilitates fast access to the open data acquired during these missions. The data will be further connected with new theoretical and simulation models and their usage will provide the expected impact of improvement of the scientific results that can be obtained from collected space data. The outputs will provide a long-term dissemination contributing to a higher level space monitoring system, and more reliable space weather forecast ability.

Lapenta, G.; SOTERIA Team

2007-12-01

398

Refined approaches for terrestrial reference frame computations  

NASA Astrophysics Data System (ADS)

Geodetic space techniques allow to determine station positions with precisions of a few millimeters. The underlying reference frame requires thus the same level of accuracy. The International Terrestrial Reference System (ITRS) is up to date realised by epoch positions and linear velocities for all the included stations. Detailed analyses, however, show that linear velocities do not fit the time dependent positions with the required accuracy. To improve the time evolution we study weekly solutions of the station positions and datum parameters. We use GPS, SLR, VLBI and DORIS solutions that are obtained from the corresponding IERS technique centres or computed at DGFI. Time series of station coordinates and datum parameters (scale, translation) are computed by aligning each individual solution to a multi-year reference (ITRF2000). The time series are analysed to detect systematic effects such as jumps or periodic signals (esp. seasonal periods). Additionally the covariance information of the networks and the station positions are investigated. As a refined approach we then combine the weekly normal equations to a multi-year TRF solution. Thereby an important aspect is the parameterisation (e.g. to include an annual period for station positions and the datum parameters). The results are discussed and compared with existing TRF solutions and geophysical models.

Meisel, B.; Angermann, D.; Drewes, H.; Gerstl, M.; Kelm, R.; Kruegel, M.; Mueller, H.; Tesmer, V.

399

Dinosaurs and the Cretaceous Terrestrial Revolution  

PubMed Central

The observed diversity of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50?Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has long been debated whether dinosaurs were part of the Cretaceous Terrestrial Revolution (KTR), from 125–80?Myr ago, when flowering plants, herbivorous and social insects, squamates, birds and mammals all underwent a rapid expansion. Although an apparent explosion of dinosaur diversity occurred in the mid-Cretaceous, coinciding with the emergence of new groups (e.g. neoceratopsians, ankylosaurid ankylosaurs, hadrosaurids and pachycephalosaurs), results from the first quantitative study of diversification applied to a new supertree of dinosaurs show that this apparent burst in dinosaurian diversity in the last 18 Myr of the Cretaceous is a sampling artefact. Indeed, major diversification shifts occurred largely in the first one-third of the group's history. Despite the appearance of new clades of medium to large herbivores and carnivores later in dinosaur history, these new originations do not correspond to significant diversification shifts. Instead, the overall geometry of the Cretaceous part of the dinosaur tree does not depart from the null hypothesis of an equal rates model of lineage branching. Furthermore, we conclude that dinosaurs did not experience a progressive decline at the end of the Cretaceous, nor was their evolution driven directly by the KTR.

Lloyd, Graeme T; Davis, Katie E; Pisani, Davide; Tarver, James E; Ruta, Marcello; Sakamoto, Manabu; Hone, David W.E; Jennings, Rachel; Benton, Michael J

2008-01-01

400

Terrain effect on terrestrial heat flow  

SciTech Connect

A new approach to topographic correction for terrestrial heat flow measurements is presented. The approach features calculation of a Fourier series fit to the surface temperature - surface evaluation data where the surface temperatures are based on a model that includes surface temperature variations due to microclimate variations. Mathematics of the terrain correction problem are similar to upward (away from source) continuation problem in gravity and magnetics so several solutions, in addition to the Fourier series approach, are available in the literature that allow an accurate calculation of the correction provided the surface boundary condition is properly specified. However, the usual boundary condition applied, a linear relation between ground surface temperature and elevation, is shown to be inadequate for drill holes in the depth range 30 to 200 m no matter how low the topographic relief. Thus a model of ground surface temperature is developed that includes the effects of elevation, slope orientation, and slope angle. Because of the effects of microclimate, the classical models that have isothermal surfaces that generally parallel the topographic surface are significantly in error in many cases, and the patterns of isotherms near the topographic surface are more complicated than was previously recognized.

Blackwell, D.D.; Steele, J.L.; Brott, C.A.

1980-09-10

401

PhenoCam: A continental-scale observatory for monitoring the phenology of terrestrial vegetation  

NASA Astrophysics Data System (ADS)

The term phenology refers to both the seasonal rhythms of plants and animals, and the study of these rhythms. Plant phenological processes, such as when leaves emerge in the spring and change color in the autumn, are highly responsive to year-to-year variation in weather as well as longer-term changes in climate, particularly as related to temperature and precipitation. Understanding and predicting the impacts of climate change on plants and ecosystems requires better data with which predictive models of phenology can be developed and tested. PhenoCam uses networked, digital cameras as multi-channel imaging sensors to track the seasonal dynamics of terrestrial vegetation across a range of ecosystem types. The original network, which began in 2006 as a project focusing on the northeast region, consists of a dozen cameras deployed at pre-existing long term research sites. At eight of these sites, cameras are co-located with eddy covariance instrumentation with which surface-atmosphere exchanges of carbon, water and energy are being measured. This provides opportunities for investigating relationships between phenology and ecosystem function and climate system feedbacks. We plan to expand PhenoCam from a regional network to a continental-scale observatory. We will deploy 20 additional cameras at FLUXNET sites across North America, spanning a wide range of vegetation types. We will further explore the feasibility of exploiting information related to phenology from an existing image archive of approximately 17,000 publicly available cameras located across the continent. We will use computer vision and machine learning approaches to develop new processing algorithms for this imagery, and will link these data products both to ground observations by USA-National Phenology Network "citizen scientists" and various satellite-based data streams, e.g. the MODIS phenology product. This project will develop predictions of how phenology may be affected by future climate change, and will quantify how future changes in phenology may impact some of the services that society derives from natural and managed ecosystems, such as agricultural crops, forest products, and clean water. In addition, the data produced from this project will be used improve the representation of phenological processes in large-scale climate models, which will help to reduce uncertainties in future climate forecasts.

Richardson, A. D.; Friedl, M. A.; Frolking, S.; Pless, R.; PhenoCam Collaborators

2011-12-01

402

Proactive Parent Communication.  

ERIC Educational Resources Information Center

Presents examples of teacher-parent interactions designed to help teachers communicate with parents. The scenarios involve a teacher communicating with parents about a struggling student, a teacher communicating with parents about a student's behavior problems, and a teacher attempting to communicate with a confrontational parent. Teacher prompts…

Babcock, Sharel; Backlund, Judy

2001-01-01

403

Digital communications by satellite  

Microsoft Academic Search

Topics in digital satellite communications are treated extensively for a readership of students or communications system designers acquainted with communications theory fundamentals and random processes. Major parts of the book are: signal quantizing and multiplexing; satellite communications; modulation and coding in distorted channels; worldwide timing by satellite relay. Some specific topics treated include: PCM quantizing, sampling of nonbandlimited signals, delta

J. J. Spilker Jr.

1977-01-01

404

Development Communication Report, 1993.  

ERIC Educational Resources Information Center

|The three 1993 issues of the newsletter "Development Communication Report" focus on the use of communication technologies in developing countries to educate the people about various social issues as well as the field of development communication itself. Agricultural communication is the theme of the first issue which contains the following…

Bosch, Andrea, Ed.

1993-01-01

405

Training total communication  

Microsoft Academic Search

Background: Many people with severe or moderate aphasia begin to use nonverbal methods of communication spontaneously, but some need special training to do so. Use of total communication, including different nonverbal techniques, is often recommended to enable communication and participation in social interaction. Emphasis has also been placed on the importance of a communication partner in facilitating interaction and co-constructing

Pirkko Rautakoski

2011-01-01

406

Development Communication Report, 1993.  

ERIC Educational Resources Information Center

The three 1993 issues of the newsletter "Development Communication Report" focus on the use of communication technologies in developing countries to educate the people about various social issues as well as the field of development communication itself. Agricultural communication is the theme of the first issue which contains the following…

Bosch, Andrea, Ed.

1993-01-01

407

Studies on moisture relationships of some aquatic and terrestrial algae  

Microsoft Academic Search

Summary  Significant variations among aquatic and terrestrial algae (L. arboricola, Oedogonium sp. and V. hamata), in moisture and hydration percentage have been observed. Both percentages proved to be significantly higher in the aquatic\\u000a forms.

S. Seth

1971-01-01

408

A Study of Terrestrial Radio Determination. Applications and Technology.  

National Technical Information Service (NTIS)

The report describes the results of a study of terrestrial radio determination (TRD) applications and technology. Considerable emphasis has been placed on automatic automotive vehicle location or monitoring (AVL or AVM) systems because almost all of the s...

J. E. Ward M. E. Connelly A. K. Tetewsky

1979-01-01

409

Lanthanum isotopic composition of meteoritic and terrestrial matter  

Microsoft Academic Search

Mass spectrometric techniques were used to measure the lanthanum isotopic composition of meteoritic and terrestrial whole rock samples weighing about 150 mg each. Measurement results are reported, and their cosmochemical implications are discussed.

Jason J.-S. Shen; Typhoon Lee; Chau-Ting Chang

1994-01-01

410

Terrestrial Impact Structures of Two Target Materials and Textures  

NASA Astrophysics Data System (ADS)

Terrestrial impact structures are divided into impacts on hard rock (type 1) and soft materials (type 2) remained at lowlands and highlands, where carbon-bearing micro-grains are material state change indicators at broken impact structures on Earth.

Miura, Yas.

2012-09-01

411

Effects of Forest Management Practices on Terrestrial Coleopteran ...  

Treesearch

Science.gov - We Participate ... Peaks of annual above-ground terrestrial activity varied among species. ... might be predicted in systems where mature forest was historically rare due to large-scale, high-intensity, and low-frequency wildfire.

412

Terrestrial Vertebrate Monitoring, Channel Islands National Park, 1993 Annual Report.  

National Technical Information Service (NTIS)

Terrestrial vertebrate monitoring was begun at Channel Islands National Park during the spring of 1993. Previously developed monitoring protocols for island fox, island deer mice, pacific slender salamanders, and several species of lizard were implemented...

C. A. Schwemm

1995-01-01

413

Solar-Terrestrial Physics: A Glossary of Terms and Abbreviations.  

National Technical Information Service (NTIS)

A glossary of terms, abbreviations, and symbols commonly encountered in solar-terrestrial physics and related fields has been prepared, to serve as a centralized reference and guide for users of the literature. (Author)

J. M. Gilliland

1967-01-01

414

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

NASA Astrophysics Data System (ADS)

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

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

2006-11-01

415

Morphological Investigations of Martian Spherules, Comparisons to Collected Terrestrial Counterparts  

Microsoft Academic Search

We studied the morphology of the Martian spherules and compared them with their terrestrial counterparts with hematite crust, collected in Venezuela and West Australian deserts, and discussed their possible formation processes.

T. Gánti; T. Pócs; Sz. Bérczi; Z. Ditroi-Pukas; K. Gal-Solymos; A. Horváth; M. Nagy; I. Kubovics

2005-01-01

416

Morphological Investigations of Martian Spherules, Comparisons to Collected Terrestrial Counterparts  

NASA Astrophysics Data System (ADS)

We studied the morphology of the Martian spherules and compared them with their terrestrial counterparts with hematite crust, collected in Venezuela and West Australian deserts, and discussed their possible formation processes.

Gánti, T.; Pócs, T.; Bérczi, Sz.; Ditroi-Pukas, Z.; Gal-Solymos, K.; Horváth, A.; Nagy, M.; Kubovics, I.

2005-03-01

417

Tracking contaminant flux from aquatic to terrestrial food webs  

EPA Science Inventory

Aquatic insects provide a critical energy subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated aquatic resource utilization and contaminant exposure among riparian invertivores (spiders and herpt...

418

Evolution of Venus' Climate and Implications for Terrestrial Exoplanets  

NASA Astrophysics Data System (ADS)

We developed a semi-analytic 1D climate model with clouds to investigate how distance to the star, planetary mass, and the radiative effects of clouds affect the lifetime of oceans on terrestrial planets around other stars.

Bullock, M. A.

2012-06-01

419

Detailed Observations of the Source of Terrestrial Narrowband Electromagnetic Radiation.  

National Technical Information Service (NTIS)

We present detailed observations of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence betwee...

W. S. Kurth

1982-01-01

420

Evolution of Ore Deposits on Terrestrial Planets (Abstract Only).  

National Technical Information Service (NTIS)

Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Co...

R. G. Burns

1991-01-01

421

FATE OF SELECTED FUNGICIDES IN A TERRESTRIAL LABORATORY ECOSYSTEM  

EPA Science Inventory

The disposition of (14)C-labeled pentachloronitrobenzene (PCNB), two of its analogues pentachlorophenol (PCP) and hexachlorobenzene (HCB), and captan was examined as seed-protectant coatings in a terrestrial microcosm chamber (TMC) in comparison to a reference compound, dieldrin ...

422

Do future commercial broadband communication satellites really need laser-communication intersatellite links (ISLs)?  

NASA Astrophysics Data System (ADS)

Large commercial satellite programs requiring ISLs are growing in number and maturing. An important segment of the commercial satellite market, and its ISL needs, is discussed in the paper. ISL value will increase as long-haul terrestrial backbones become increasingly congested. Providing interregional and intercontinental connectivity via ISL presents far lower cost and fewer problems than relying on terrestrial fiber-optic networks. To demonstrate this, a new metric is proposed which allows 'apples-to- apples' cost/performance comparisons between laser communications in GEO, LEO, and terrestrial fiber-optics. ISL requirements in to the next decade are predicted >= 50-100 Gb/s full duplex. Many attitudinal changes must be embraced among those who choose to focus on this new commercial business. Foremost among these is a preponderance to delivering fully acceptable hardware fast and at low cost, as opposed to merely designing such. Considerable attention must be given business considerations foreign to professionals who have spent time in the government or government contracting sectors. Successful ISL customers will come to recognize that ISLs are not commodity products. Failure to embrace these attitudes will nonetheless constitute decision to which the commercial market, and particularly the financial market, will appropriately respond.

Freidell, James E.

1997-05-01

423

Responses of terrestrial Antarctic ecosystems to climate change  

Microsoft Academic Search

Antarctic terrestrial biota are generally limited by the inexorably linked environmental factors of low summer temperature\\u000a and lack of available water. However, in parts of the Antarctic, both these factors are changing rapidly on contemporary timescales.\\u000a Terrestrial biota have concurrently been faced with changes in the timing of UV-B maxima associated with spring ozone depletion.\\u000a The region of the Antarctic

P. Convey; R. I. L. Smith

424

Responses of Terrestrial Antarctic Ecosystems to Climate Change  

Microsoft Academic Search

\\u000a Abstract  Antarctic terrestrial biota are generally limited by the inexorably linked environmental factors of low summer temperature\\u000a and lack of available water. However, in parts of the Antarctic, both these factors are changing rapidly on contemporary timescales.\\u000a Terrestrial biota have concurrently been faced with changes in the timing of UV-B maxima associated with spring ozone depletion.\\u000a The region of the Antarctic

P. Convey; R. I. L. Smith

2006-01-01

425

Statistical analysis of chemical components of moon and terrestrial planets  

NASA Astrophysics Data System (ADS)

Materials of model chemical analysis of the moon and terrestrial planets are examined by some multivariate statistical analyses (cluster analysis and discriminant analysis). The results show that the moon's constituents are more closely related to those of Mars and the asteroids than other terrestrial planets, including the earth. Therefore, it is suggested that the moon possibly came from the region located at the outer side of earth's formation region.

Xu, D.-Y.

1985-01-01

426

Novel Bioactive Natural Products from Marine and Terrestrial Sources  

Microsoft Academic Search

Recent chemical studies on the marine soft corals and terrestrial plants have resulted in the isolation of several novel compounds.\\u000a The soft corals, Pseudopterogorgia elisabethae and Cladiella species yielded several novel terpenoids, exhibiting antimicrobial activities. New steroids were isolated from terrestrial\\u000a fungi, Mucor plumbeus and Coprinus micaceus . Phytochemical studies on the Buxus hyrcana, collected from Iran, have yielded steroidal

Athar Ata

427

Catastrophic events on the terrestrial planetary bodies in Phanerozoic period  

Microsoft Academic Search

Comparative analysis of the catastrophic events on the moon, the Earth, Mars and Venus 0.037 to 1.0 b.y. ago is provided. The correlation between the intensity of cratering on the terrestrial planetary bodies and cosmic age of meteorites is shown. Synchronous splash of meteoritic bombardment of the moon and the terrestrial planets 500-700 m.y. ago is noted. That is one

A. B. Korol; K. K. Kamensky

1997-01-01

428

Martian mud volcanism: Terrestrial analogs and implications for formational scenarios  

Microsoft Academic Search

The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that equivalent Martian processes likely required discrete sedimentary depocenters, volatile-enriched strata, buried rheological instabilities, and a mechanism of destabilization

James A. Skinner Jr.; Adriano Mazzini

2009-01-01

429

Ecological Classification of Terrestrial Algal Communities in Polar Environments  

Microsoft Academic Search

\\u000a Cyanobacteria (Cyanoprokaryota, Cyanophyta) and eukaryotic algae (the terms 'algae'and 'algal'in the text always includes\\u000a Cyanobacteria, unless further specified) play an important role in polar terrestrial ecosystems (e.g. Holdgate 1970; Laws 1984; Chernov 1985; Walton 1987; Aleksandrova 1988; Vincent 1988; Kerry and Hempel 1990; Friedmann 1993; Hempel 1994; Fogg 1998; Priscu 1998). They are widespread in all polar terrestrial environments, including

J. Elster

430

The carbon balance of terrestrial ecosystems in China  

Microsoft Academic Search

Global terrestrial ecosystems absorbed carbon at a rate of 1-4Pgyr-1 during the 1980s and 1990s, offsetting 10-60 per cent of the fossil-fuel emissions. The regional patterns and causes of terrestrial carbon sources and sinks, however, remain uncertain. With increasing scientific and political interest in regional aspects of the global carbon cycle, there is a strong impetus to better understand the

Shilong Piao; Jingyun Fang; Philippe Ciais; Philippe Peylin; Yao Huang; Stephen Sitch; Tao Wang

2009-01-01

431

Terrestrial Carbon Cycle Dynamics under Recent and Future Climate Change  

Microsoft Academic Search

The behavior of the terrestrial carbon cycle under historical and future climate change is examined using the University of Victoria Earth System Climate Model, now coupled to a dynamic terrestrial vegetation and global carbon cycle model. When forced by historical emissions of CO2 from fossil fuels and land-use change, the coupled climate-carbon cycle model accurately reproduces historical atmospheric CO2 trends,

H. Damon Matthews; Andrew J. Weaver; Katrin J. Meissner

2005-01-01

432

Simulation of carbon isotope discrimination of the terrestrial biosphere  

Microsoft Academic Search

We introduce a multistage model of carbon isotope discrimination during C3 photosynthesis and global maps of C3\\/C4 plant ratios to an ecophysiological model of the terrestrial biosphere (SiB2) in order to predict the carbon isotope ratios of terrestrial plant carbon globally at a 1° resolution. The model is driven by observed meteorology from the European Centre for Medium-Range Weather Forecasts

N. S. Suits; A. S. Denning; J. A. Berry; C. J. Still; J. Kaduk; J. B. Miller; I. T. Baker

2005-01-01

433

Terrestrial Mammals of Bulgaria: Zoogeographical and Ecological Patterns of Distribution  

Microsoft Academic Search

Our present knowledge of the terrestrial mammals of Bulgaria is reviewed on the basis of published records and original data\\u000a collected in 1990–2002. The study is based on 93 species of terrestrial mammals. They are classified into four faunal complexes\\u000a reflecting the influence of historical and environmental factors. The spatial differentiation of the mammalian fauna is considered\\u000a within a network

Vasil Popov

434

Survey of protected terrestrial vertebrates on the Oak Ridge Reservation 1995 annual progress report  

SciTech Connect

This progress report discusses surveys of protected terrestrial vertebrates on the Oak Ridge Reservation (ORR) from October 1994 through September 1995. These surveys are important to help avoid or minimize potential impacts of projects on the ORR to species listed as threatened, endangered, or in need of management by the US Fish and Wildlife Service and the Tennessee Wildlife Resources Agency. Currently, there are 69 species of federally or state-listed terrestrial vertebrates that may occur in Tennessee. Not all of these are expected to occur on the ORR, nor do resources permit comprehensive sampling for all of them over the entire ORR. To effectively organize sampling efforts, listed animal species that might be present were targeted using a prioritization system based on historical and recent sightings, species distributions, literature reviews, and personal communications. Sampling was conducted during the time of the year when each targeted species would most likely be encountered. Several trapping and surveying methods were used, including pitfall traps, Sherman traps, seining, artificial covers, and cave and avian surveys.

Vail, E.R.; Mitchell, J.M.; Webb, J.W.; King, A.L.; Hamlett, P.A.

1995-11-01

435

Terrestrial models for development of methods to search for life on Mars and other planetary bodies  

NASA Astrophysics Data System (ADS)

Successful missions to Mars, Europa and other bodies of the Solar system have created a prerequisite to search for extraterrestrial life. The first attempts of microbial life detection on the Martian surface by the Viking landed missions gave no biological results. Microbiological investigations of the Martian subsurface ground ice layers seem to be more promising. It is well substantiated to consider the Antarctic ice sheet and the Antarctic and Arctic permafrost habitats as terrestrial analogues. The results of our long-standing microbiological studies of the Antarctic ice would provide the basis for detection of viable microbial cells on Mars. Our microbiological investigations of the most ancient and deepest strata of the Antarctic ice sheet for the first time gave evidence for the natural phenomenon of long-term anabiosis (preservation of viability and vitality for millennia years). A combination of classical microbiological methods, epifluorescence microscopy, SEM, TEM, molecular diagnostics, radiolabeling and other techniques made it possible for us to obtain a convincing proof of the presence of pro- and eukaryotes in the Antarctic ice sheet. In this communication we will review and discuss some critical issues related to the detection of viable microorganisms in cold terrestrial environments with regard to future search for microbial life and/or its biosignatures on extraterrestrial objects.

Abyzov, S. S.; Duxbury, N. S.; Fukuchi, M.; Hoover, R. B.; Kanda, H.; Mitskevich, I. N.; Mulyukin, A. L.; Naganuma, T.; Poglazova, M. N.; Ivanov, M. V.

436

Improving Employee Communications  

SciTech Connect

This report summarizes the findings and recommendation of the Sandia/California Site Communications Team based on activities during FY98. The important conclusions are that effective communications are everyone's business; careful planning and execution are required for effective communications; and communication planning can be described in steps easily understood by everyone. Included in this report is a quick reference (toolkit) for communication planning and implementation.

A. R. Pomplun; B. J. Kelley; B. L. Schrader; R. C. Christma; R. H. Tucker

1999-01-01

437