摘要:

During its sixth scientific assembly in Exeter, United Kingdom, the International Association of Geomagnetism and Aeronomy (IAGA) designated September 1991–March 1993 as the International Equatorial Electrojet Year (IEEY). During this period, intensive and coordinated campaigns on the equatorial electrojet (EEJ) and related aeronomic phenomena are being conducted using a variety of observational techniques at low latitudes. IAGA urges all concerned scientific communities to participate actively in this program. The IEEY is an international cooperative project to improve our understanding of the geophysical, aeronomic, electrodynamic, and plasma processes that control the EEJ current, especially its spatial structure, space and time variations, instabilities, and induced effects. It offers interesting opportunities for EEJ study groups around the world to intensify their activities in a coordinated way. Here, we describe the scientific perspectives and goals of the IEEY, which is coordinated by IAGA's Inter‐Divisional Commission on Developing Countr

ISSN:0002-8606    

DOI:10.1029/91EO00044

年代:1992

数据来源: WILEY

摘要:

A scientific panel was unable to reach a consensus on the hydrotectonic theory acting at Yucca Mountain, Nev., put forth by Department of Energy geologist Jerry Szymanski. The panel's reports, reflecting majority and minority opinions, were released late last year and form one part of DOE's overall site characterization of Yucca Mountain as a storage site for high‐level nuclear waste. DOE has also asked the National Academy of Sciences to review Syzmanski's theory and will incorporate its results into the site assessment.The five‐person DOE panel convened early in 1990 to begin its review of Szymanski's concepts, data, and interpretations laid out in his 1989 report, “Conceptual Considerations of the Yucca Mountain Groundwater System with Special Emphasis on the Adequacy of this System to Accommodate a High‐Level Nuclear Waste Repository.” After meeting several times throughout the year in the field and with Szymanski and realizing there were conflicting opinions within the review group, the external panel decided in December 1990 to prepare majority and minority reports. DOE also asked the panel to make recommendations to the agency on furthe

ISSN:0002-8606    

DOI:10.1029/91EO00046

年代:1992

数据来源: WILEY

摘要:

If scientists fail to set priorities for research spending, someone else will, said Rep. George Brown, Jr. (D.‐Calif.) at a recent space policy symposium in Washington, D.C. Addressing one of his now‐familiar themes—priority‐setting—the chair of the House Space, Science, and Technology Committee called for apportioning research support based, above all, on scientific merit. Otherwise, “science funding may be increasingly decided by ‘political pork’ awarded to localities based on political rather than scientific goals,” he said.At a January 24 forum of the National Academy of Sciences' Space Studies Board, Brown stressed that space science objectives must match the nation's overall “science and technology agenda.” Scientists and policy‐makers should work together to advance “explicit social, economic, and political goals,” he said. However, “if Congress perceives that scientists view research funding as a right rather than an opportunity that comes with a responsibility, th

ISSN:0002-8606    

DOI:10.1029/91EO00047

年代:1992

数据来源: WILEY

摘要:

The AGU 1991 Fall Meeting, held in San Francisco December 9–13, was the largest national AGU meeting ever held. Meeting participation continued the steady growth trend set throughout the previous decade. A total of 4,037 papers and posters were presented, and by Friday noon of the meeting over 5,500 members had registered.Several special events were scheduled to inform and engage members on societal and programmatic aspects of our science. AGU's Committee on Education and Human Resources sponsored an open forum that addressed opportunities and problems associated with dual‐career couples. A discussion of NASA's strategic plan by Berrien Moore and Joseph Alexander drew a large audience, and a special session on societal aspects of the Mt. Pinatubo eruption drew an overflow crowd. Two special lectures— “Plumes, Plates, and Deep Earth Structure” by Don L. Anderson and “New Frontiers in Aeronomy: Effects of Global Atmospheric Change” by P. M. Banks‐also drew

ISSN:0002-8606    

DOI:10.1029/91EO00050

年代:1992

数据来源: WILEY

摘要:

Synthetic aperture radar (SAR) imaging of the ocean surface promises to be an important tool in ocean remote sensing. The long‐range goal of the work reported here is to understand SAR imaging in sufficient detail that airborne and/or spaceborne SARs become reliable tools for oceanic research and operational use.TOWARD (Tower Ocean Wave and Radar Dependence Experiment) [seeShemdin, 1988, 1990], a predecessor experiment to the SAR and X‐Band Ocean Nonlinearities Experiment at Chesapeake Light Tower (SAXON:CLT), provided a comprehensive data set to test the theoretical concepts advanced on SAR imaging of the ocean surface. A significant achievement of TOWARD is determining that none of the then available theories on SAR imaging of long surface waves could explain all the SAR observations satisfactorily. Improved models immediately followed as a consequence of the TOWARD finding. In spite of the significant insights gained in TOWARD, gaps remain in understanding radar backscatter from the sea surf

ISSN:0002-8606    

DOI:10.1029/91EO00052

年代:1992

数据来源: WILEY

摘要:

In the interlude between spacecraft encounters with Jupiter, Earth‐bound observers using clever and powerful techniques have made substantial headway in monitoring two major phenomena: volcanos on Jupiter's moon Io (most active in the solar system) and Jupiter's magnetosphere (largest and densest of all the planets). While these two may seem unrelated, planetary scientists believe they are quite closely tied. Astronomers are working together to probe the fundamental and enigmatic connection between volcanos and magnetospheres.Volcanic activity on Io is powered not by radioactive heating, as it is on Earth, but by the continual flexing of Io by Jupiter's intense gravitational field, which generates heat as in a rapidly flexed tennis ball. Most of this heat is eventually radiated into space from a series of hot volcanic centers, or “hot spots,” where the surface is up to several hundred degrees hotter than its surroundings. The heat radiation is so intense that Io literally “glows in the dark” at infrared wavelengths, allowing astronomers with infrared telescopes to follow the frequent changes in the level of volcanic

ISSN:0002-8606    

DOI:10.1029/91EO00053

年代:1992

数据来源: WILEY