Science Working Group Research Articles

Cyclotron Observations of Binary X-Ray Pulsars

Suzaku has observed some cyclotron X-ray pulsars in the SWG (Science working group) phase. Suzaku detected the cyclotron feature in the lowest luminosity from A0535+26. In Her X-1, Suzaku measured new data points in the year-long trend of cyclotron resonance energy, and searched for the second harmonic structure. The RXTE observations of X0331+53 gave the second example on changing the resonance energy and indicated that the energy ratio of the 2nd and 1st cyclotron energies is apart from two.

Introduction to special section: Small‐Scale Sea Ice Kinematics and Dynamics

[1] Away from the ice margins, the response of the ice cover to large-scale gradients in atmospheric and oceanic forcing is concentrated along narrow zones of failure (up to tens of kilometers in width) resulting in openings, closings or shears. In winter, openings dominate the local brine production and heat exchange between the underlying ocean and the atmosphere. Convergence of the pack ice forces the ice to raft or pile up into pressure ridges and to be forced down into keels, increasing the ice-ocean and ice atmosphere drag. A combination of openings and closings is typical when irregular boundaries are sheared relative to one another. These processes shape the unique character of the thickness distribution of the ice cover and have profound impacts on the strength of the ice and its deformation properties over a wide range of temporal and spatial scales. Understanding the basin-scale mechanical character of the sea ice cover is thus of importance in modeling its behavior in a changing climate and in facilitating operational applications. [2] In widely used models of sea ice, the representation of these processes is typically included in an aggregate and parameterized form based on simplifying assumptions. In the past, progress in model validation and improvements has been slowed by the lack of suitable observations. Except for focused field campaigns, observations of the above processes from buoy drift are limited by spatial sampling that is typically several hundred kilometers. Only with sea ice kinematics derived from high resolution Synthetic Aperture Radar (SAR) imagery have we been able to approach the spatial length scale required to observe these processes. In the late 1980s and most of the 1990s, the availability of small volumes of ice motion data from the European SAR satellites (ERS-1, 2) have allowed examination of sea ice strain rates at 5–10 km length scales and demonstrated the utility of these measurements for sea ice studies. However, the narrow swath of these early SAR missions obscures the spatial extent of the deformation patterns beyond 100 km. Launched in November of 1996, the wide-swath coverage of the RADARSAT imaging radar offers a tool capable of providing high resolution ( 100 m) observations of the Arctic ice cover. Since 1997, routine 3-day RADARSAT data of the Arctic Ocean have been acquired and processed into imagery at the Alaska Satellite Facility. The NASA-funded RADARSAT Geophysical Processing System (RGPS) [Kwok, 1998], a joint project of the Alaska Satellite Facility and the Jet Propulsion Laboratory is a program for producing fine-scale sea ice motion products. The program objective is to provide a dataset suitable for understanding the basin-scale behavior of sea ice kinematics on a seasonal and inter-annual time scale, and for improving ice dynamics. Thus far, four winters and three summers of the RADARSAT acquisitions have been processed and the data products are posted at the following website: http://www-radar.jpl.nasa.gov/rgps/ working2/radarsat.html. [3] The availability of ice motion data from the RGPS program has allowed a more detailed and unprecedented look at the small-scale time-varying deformation of the ice cover [Kwok, 2001]. The RGPS observations point to the importance of understanding the consequence of ice pack as an anisotropic material with large-scale oriented fracture patterns. With the increasing resolution of coupled iceocean models that approaches the widths of leads, high resolution observations like that of the RGPS are needed for model development and validation. Simulation results can now be examined in detail. For climate studies, the impact of an anisotropic ice cover on surface heat and mass balance is not well understood. The RGPS dataset is a crucial component in the testing of new models that accounts for the spatial and temporal characteristics of these patterns. [4] At the 2004 RGPS Science Working Group meeting in Seattle, the participants showed that there were sufficient potential papers and new results to justify a Journal of Geophysical Research special section to showcase recent work on this topic. They highlight the importance of highresolution satellite observations for sea ice studies. There are also, of course, other papers that discuss these topics in other issues of JGR, as well as other journals. We encourage interested readers to examine these sources. The resulting collection is a special section that contains a mix of eight papers addressing a range of topics in modeling and observations of small-scale kinematics and dynamics of the sea ice cover: five papers address the issues of smallscale modeling, and three summarize the laboratory, in situ and satellite observations that describe the small-scale behavior of the sea ice cover. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, C11S21, doi:10.1029/2006JC003877, 2006 Click Here for Full Article

Natural capital: The limiting factor: A reply to Aronson, Blignaut, Milton and Clewell

Ecological engineering, ecological economics and ecological restoration are all emerging transdisciplinary fields dedicated to tackling wickedly complex problems at the interface of the economic system and the global ecosystems that sustain and contain it. Though these fields emerge from different disciplinary backgrounds, each espouses a systems approach, and each offers a critical part of the solution to the problems we face in the 21st century (Mitsch and Jorgensen, 2003; Daly and Farley, 2004; Society for Ecological Restoration International Science and Policy Working Group, 2004). As emerging transdisciplines, each is still struggling to build consensus on the terminology, methodologies and tools that characterize more mature areas of studies: given our common goals, this consensus should be built across all three fields. Dialogue among the practitioners of these complementary transdisciplines is therefore essential, and we welcome this opportunity for dialogue with Aronson, Blignaut, Milton and Clewell (hereafter

Identifying grand research questions in the solid‐earth sciences

Progress in the solid‐Earth sciences has been remarkable over the past few decades, driven by the availability of new instruments, improved modeling capabilities, reduced barriers to cooperation with scientists in other countries, and increased coordination with other disciplines, such as astronomy and biology. With research advancing on such a wide front, it can be difficult to define the frontiers of scientific inquiry and to convey that information in a way that captures the imaginations of the scientific community, the U.S. Congress, U.S. federal agencies, and the general public.At the request of program managers at the U.S. Department of Energy, U.S. National Science Foundation, U.S. Geological Survey, and NASA, the U.S. National Academies has assembled a committee of experts to identify the grand research questions driving the solid‐Earth sciences. Although other reports have identified research priorities in this area, just a few (such as “Living on a restless planet,” 63 pp., NASA Solid Earth Science Working Group, Pasadena, Calif., 2002) have cast them mainly as compelling, fundamental science questions. Such ‘big picture’ questions may require decades to answer, and research support from many government agencies and organizations. The answers to these questions could profoundly affect our understanding of the Earth.

Preparing for the era of ELTs: precursor surveys, coordinated campaigns and operations planning

We illustrate the need for planning surveys and coordinated observations, using representative science cases developed for ELTs by the GSMT Science Working Group. We conclude that enabling surveys and coordinated observations is critical to ELTs and that ground-based optical and radio and space-based facilities are needed. A world-wide systems approach is needed to support ELT campaigns. We discuss early planning for ELT operations, based on discussions in progress within the TMT partnership. We conclude that developing an architecture to accommodate end-to-end observation and data management will be essential to achieving near-term and legacy goals.

An invitation to an alcohol industry lobby to help decide public funding of alcohol research and professional training: a decision that should be reversed.

An invitation to an alcohol industry lobby to help decide public funding of alcohol research and professional training: a decision that should be reversed.

Plan for living on a restless planet sets NASA's solid Earth agenda

What are the most important challenges facing solid Earth science today and over the next two decades? And what is the best approach for NASA, in partnership with other agencies, to address those challenges? A new report, Living on a Restless Planet, provides a blueprint for answering these questions. The top priority for a new spacecraft mission in the area of solid Earth science over the next 5 years, according to this report, is a satellite dedicated to Interferometric Synthetic Aperture Radar (InSAR).At the request of NASA, the Solid Earth Science Working Group (SESWG) developed a strategy for the highest priority objectives in solid Earth science for the space agency over the next 25 years. The strategy addresses six challenges that are of fundamental scientific importance, have strong implications for society, and are amenable to substantial progress through a concerted series of scientific observations from space.

A consistent approach to definitions and symbols in fisheries acoustics

Long-standing problems with acoustical terminology in fisheries applications such as echo-integration indicate the need for a more consistent approach. Based where possible on existing terms, a scheme of explicitly named quantities is proposed, backed by clearly stated definitions and preferred symbols. The emphasis is on scattering phenomena because the terminology in this area presents the main source of difficulty. Starting with the scattering equations for a small target, the volume, area, and line coefficients relevant to multiple, distributed targets are defined, leading to practical formulas for the important application of remote biomass estimation from echo-integration. The aim is to incorporate, as far as possible, common practice in fisheries-acoustics terminology and related fields. The developed scheme has been commended by the ICES Fisheries Acoustics Science and Technology Working Group as a constructive approach to better communication standards in fisheries-acoustics publications.

A suggested method for reporting landslide remedial measures

A brief list of landslide remedial measures is presented and a format for reporting landslide remediation is suggested. They make useful additions to the Landslide Report proposed by the International Union of Geological Sciences Working Group on Landslides (formerly the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory).

The Next Generation Space Telescope

The Next Generation Space Telescope (NGST) will be an 8 m deployable telescope, radiatively cooled to 30 K and diffraction-limited at 2 μm, operating at the Sun-Earth Lagrangian point L2. It will be built by a partnership of NASA, ESA, and CSA (Canadian Space Agency). The camera sensitivity should be limited by the zodiacal light for wavelengths < 10 μm. The main scientific objectives are the study of the origin and evolution of galaxies, stars, and planets, beginning with the first luminous objects to form from the Big Bang. Other objectives include studies of dark matter, supernovae, the intergalactic medium, gamma ray bursts, star ages, and exobiology. The telescope will be operated like the Hubble Space Telescope (HST) by the Space Telescope Science Institute, with all observing programs openly solicited and selected by peer review.The NGST scientific requirements originated with the report of the Dressler Committee HST & Beyond. The instruments recommended by the Ad Hoc Science Working Group (ASWG) include 1) a wide field near infrared (NIR) camera with an 8K2 detector array covering 0.6 - 5 μm, 2) a multi-object NIR spectrograph capable of simultaneously observing > 100 objects with a resolution of R (λ/δλ) = 1000, and 3) a combined mid-infrared (MIR) camera and spectrograph from 5-27 μm, with a resolution of R > 1500.

The IPCC Third Assessment Report on the Scientific Basis of Climate Change

The Intergovernmental Panel on Climate Change (IPCC) has recently completed its Third Assessment Report on the Scientific Basis of Climate Change. The report builds on previous IPCC assessment reports in 1990 and 1995 and has been in preparation for the past three and a half years through the work of more than 500 scientists world wide who have been taking stock of the research findings reported in some 4000 peer—reviewed scientific papers. The report consists of a Summary for Policymakers, a Technical Summary and an underlying detailed report of fourteen chapters. The Summary for Policymakers was approved on a line by line basis by an intergovernmental session of the science working group (Working Group 1) of the IPCC, held in Shanghai, China on 17–20 January 2001, with the participation of some 45 of the 122 Lead Authors and official government delegations from 99 countries. The report concludes that, although many uncertainties remain, the past five years of observations and research have provided stronger evidence than hitherto of a human impact on global climate and increased confidence in the capability of climate models to project future global climate trends for a range of emission scenarios through the twenty first century. This article, which is based, in part, on the author's experience as Principal Delegate of Australia to the IPCC and as a member of the IPCC Bureau since 1994, describes the operation of the IPCC assessment process and the preparation, approval and main conclusions of the science component of the Third Assessment Report.

John Alexander Simpson

3 NOVEMBER 1916 * 31 AUGUST 2000 JOHN SIMPSON was an experimental physicist whose broad view of science, education, and the politics of nuclear energy played a significant role in those activities throughout the second half of the twentieth century. He worked on the Manhattan Project during World War II and was a founding member and the first chairman of the Atomic Scientists of Chicago, formally established 7 August 1945, the day after the atomic (nuclear) bomb burst at Hiroshima. This activity led to his participation in setting up the Bulletin of the Atomic Scientists the same year, with its familiar doomsday clock on the cover to show the estimated risk of nuclear annihilation during the cold war at any given time. Over the years the articles published in the Bulletin tracked the military and political implications of the bomb, commenting on possible rational courses of action. It was widely read and served as a guiding light through the long years of darkness. Henry Luce was so impressed with the concept of the Bulletin that he provided the Atomic Scientists of Chicago with two full pages in the 25 October 1945 issue of Life magazine to expound a reasoned argument presenting their case. Simpson joined the faculty of the University of Chicago in 1945 as an instructor in the physics department and immediately took leave of absence to work as an unofficial adviser to Senator Brian McMahon of Connecticut, an association leading to the McMahon Act of 1946, which placed nuclear energy in civilian hands, rather than leaving it as a military enterprise. The McMahon Act was a fundamental step in the history of governmental administration of nuclear energy. Simpson was continually aware of the future implications of the activities of the present. His efforts concerning the handling of nuclear energy were a direct consequence of this world view, and the ongoing success of his scientific work reflected it. He was a booster of his students and his colleagues and of the University of Chicago, and he would urge people to think about what they wanted to be doing ten years in the future in order to lay plans for getting there. He brought the present writer and others to Chicago and nurtured them through the fledgling years of their careers. When Simpson was appointed to the Compton Chair in physics in 1974 he used the funds that came with the chair to establish the Compton Lectures for the public. Junior staff members are honored by appointment as Compton Lecturer for a quarter. It is a substantial responsibility, and the lectures are inevitably excellent, with gratifying public response. In 1982 he established the Space Science Working Group in Washington, D.C., so that the space science laboratories around the country could communicate more effectively with NASA and Congress. He was the first chairman of the group, which came to be a useful means of conversing with the government. Simpson applied the same visionary approach to his scientific research, looking ahead even as he was in the midst of a scientific success arising from earlier planning. He took up his position as an active faculty member in the physics department at the University of Chicago in 1946, and became intrigued by Scott Forbush's discovery of modest time variations of cosmic rays. Cosmic rays had been studied since their existence was established in 1912. It was shown in 1929 that they are particles, rather than rays of some sort, and during the postwar years that they are made up of protons with a small number of heavier nuclei, all traveling at nearly the speed of light. They have tremendous energies, and they penetrate into the atmosphere, where they make hard collisions with the nuclei of the atoms of air, producing an energetic spray of downward-moving protons, neutrons, mesons, electrons, positrons, and gamma rays-cosmic shrapnel. At the bottom of the atmosphere mu mesons streak through the air, knocking out occasional electrons to create positive and negative ions. …

The Three-Dimensional Structure of the Zodiacal Dust Bands

Using observations of the infrared sky brightness by the Cosmic Background Explorer (COBE)11The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the Cosmic Background Explorer (COBE). Scientific guidance is provided by the COBE Science Working Group. GSFC is also responsible for the development of the analysis software and for the production of the mission data sets.Diffuse Infrared Background Experiment (DIRBE) and Infrared Astronomical Satellite (IRAS), we have created maps of the surface brightness Fourier-filtered to suppress the smallest (< 1°) structures and the large-scale background (>15°). Dust bands associated with the Themis, Koronis, and Eos families are readily evident. A dust band associated with the Maria family is also present. The parallactic distances to the emitting regions of the Koronis, Eos, and Maria dust bands were found to be 1.4 to 2.5 AU. A weak dust band associated with the Eunomia/Io family is evident, together with another weak and previously unattributed dust band, which may split further into two band pairs, potentially associated with the Hygiea or Vesta family. The brightnesses of the blended Themis/Koronis bands and the Eos dust band vary with ecliptic longitude, such that the northern or southern component of the band pair becomes brighter when its tilt brings it into the ecliptic plane. We attribute the brightness variations to the motion of the Earth within the emitting region, and conclude that at least some dust-band particles are on Earth-crossing orbits. For the Themis and Koronis families, the tilt is sufficient that the Earth may pass to the edges of the emitting region, where the density is highest, leading to “glints” two or four times a year. We compared the observed distributions to theoretically motivated, empirical models for the three-dimensional distribution of asteroid family dust. In the torus model, the dust is distributed among the asteroid family members with the same distributions of proper orbital inclination and semimajor axis but a random ascending node. In the migrating model, particles are presumed to be under the influence of Poynting–Robertson drag, so that they are distributed throughout the inner Solar System. The migrating model is better able to match the parallactic variation of dust-band latitude as well as the 12- to 60-μm spectrum of the dust bands. The annual brightness variations can be explained only by the migrating model. Upper limits are placed on the dust density associated with the Nysa and Flora families—both of the large, inner-belt families with wide inclination dispersions. The association of five (and potentially seven) dust bands with the largest asteroid families suggests that dust bands are an integral part of asteroid families. If nonfamily asteroids produce dust at a rate similar to that of the families with the lowest dust density, then they can account for the brightness of the zodiacal light in the ecliptic.

History of the ASHS Working Group on Growth Chambers and Controlled Environments, 1969–96: A Case Study of Involvement

A history of the American Society for Horticultural Sciences Working Group includes establishment and goals; publication of a growth chamber manual; development of standardized measurement and reporting guidelines, quality assurance recommendations, a list of recommended instruments, standardized cultural procedures, and a standardized instrument package; and an instrument calibration program. Other highlights include information exchange with other organizations, evaluation of long-wave radiation effects in growth chambers, cooperation with industry, improved characterization of air movement, and cooperation with other American and international societies.

ISO-SWS Spectral Characterization of Stars

Spectral classification in the infrared is necessary to complete the spectral classification in the visual and to understand the physics and evolution of stars. A major contribution was made by the IRAS Low Resolution Spectrometer, which allowed a characterization of the sources according to both spectral features and general shape of the energy distribution in the 8–22 µ,m (IRAS Science Working group, 1986). However, spectra obtained with the ISO Short Wavelength Spectrometer (SWS) (de Graauw et al. 1996, Kessler et al. 1996) provide the basis for a more complete data-base. Compared with LRS, SWS spectra cover a wider flux range and a wider spectral range 2.4–44.5 µm at a significantly higher spectral resolution. This work is part of an extensive ISO dedicated time program STARTYP1/2, which aims to provide a comprehensive spectral classification scheme of over 700 of the brightest representative infrared sources.

Principles for the selection of doses in chronic rodent bioassays. ILSI Risk Science Working Group on Dose Selection.

Dose selection in chronic rodent bioassays has been one of the most debated issues in risk assessment. The Committee on Risk Assessment Methods of the National Research Council attempted, but failed, in 1993 to reach consensus on how to select doses for chronic rodent bioassays. However, a more recent effort conducted by the ILSI Risk Science Institute has resulted in a consensus set of principles for dose selection, including selection of the highest dose for chronic rodent bioassays. The principles encourage a move away from sole reliance on a maximum tolerated dose (MTD), as it has been traditionally defined (primarily by body weight and histopathology), and toward the use of sound scientific and toxicologic principles for the selection of all doses in the chronic bioassay. Specifically, the principles recommend that dose selection for chronic studies must be based on sound toxicologic principles; dose selection should consider human exposure; dose selection should be based on a variety of endpoints and effects derived from prechronic studies; and dose selection should consider physicochemical and other factors. Implementation of the principles internationally will have two important benefits; improvement in the quality and consistency of the rodent bioassay and international harmonization of dose selection procedures.

The Milky Way, Local Galaxies, and the Infrared Tully‐Fisher Relation

Using the near-infrared fluxes of local galaxies derived from Cosmic Background Explorer (COBE)/ Diffuse Infrared Background Experiment (DIRBE)COBE data sets were devloped by the NASA Goddard Space Flight Center under the guidance of the COBE Science Working Group and were provided by the National Space Science Data Center (NSSDC). J- (1.25 μm) K- (2.2 μm), and L-band (3.5 μm) maps and published Cepheid distances, we construct Tully-Fisher (TF) diagrams for nearby galaxies. The measured dispersions in these luminosity-line width diagrams are remarkably small: σJ = 0.09 mag, σK = 0.13 mag, and σL = 0.20 mag. These dispersions include contributions from the intrinsic TF relation scatter and the errors in estimated galaxy distances, fluxes, inclination angles, extinction corrections, and circular speeds. For the J and K bands, Monte Carlo simulations give a 95% confidence interval upper limit on the true scatter in the TF diagram of σJ ≤ 0.35 and σK ≤ 0.45.

A suggested method for describing the rate of movement of a landslide : ANON (International Union of Geological Sciences Working Group on Landslides), Bulletin — International Association of Engineering Geology, 52, 1995, pp 75–78

A suggested method for describing the rate of movement of a landslide : ANON (International Union of Geological Sciences Working Group on Landslides), Bulletin — International Association of Engineering Geology, 52, 1995, pp 75–78

ESS Science case is drawn together

Abstract The ESS Science Working Group met for a final workshop in Firenze on May 23–25, 1996, kindly hosted- and very effectively organized-by Fabrizio Barocchi, with support from the Area di Ricerca di Firenze of the Italian CNR, and the Firenze section of the Istituto Nazionaledi Fisicadella Materia. The workshop was also attended by Professor Norbert Kroo (Budapest) for the European Science Foundation, Dr. JGrgen Kjems (Risp)) (Chairman, ESS Council), Dr. Andrew Taylor (ISIS) (ESS Council Secretary), and Dr. Giinther Bauer (PSI), the link man between the ESS Target Group and Science Working Group.

Mission in the works promises precise global topographic data

Significant deficiencies in the quality of today's topographic data severely limit scientific applications. Very few available data sets meet the stringent requirements of 10–30 m for global digital topography and 5 m or better vertical accuracy, and existing satellite systems are unlikely to fulfill these requirements. The Joint Topographic Science Working Group, appointed by NASA and the Italian Space Agency, concluded that radar interferometry coupled with a laser altimeter would be the most promising approach for improving data quality. By providing its own illumination at a wavelength Ion g enough to (e.g., λ = 25 cm) to penetrate clouds and rain, the interferometer would provide a global, uniform high‐quality topographic data set. One mission under study, TOPSAT, is well positioned to fill this niche and promises to pave the way toward a more standardized and precise topographic database. TOPSAT would be an international mission, designed to make use of recent technology advances in such programs as NASA's New Millennium. It could be ready to launch by the end of this decade.