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1. |
Microwave polarization inversion observed |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 42,
1991,
Page 449-454
Jeffrey W. Brosius,
Gordon D. Holman,
Joan T. Schmelz,
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摘要:
An inversion of solar active region microwave polarization was observed during the Coronal Magnetic Structures Observing Campaign (CoMStOC) [Brosius et al., 1992;Nitta, 1991;Schmelz and Holman, 1991;Schmelz, 1991;Schmelz et al., 1988]. This campaign, carried out in November and December 1987, was intended to improve our understanding of active region coronal plasmas and magnetic fields. The intensity and polarization of solar active region microwave emission provides probes of the coronal magnetic field. When combined with simultaneous x‐ray and photospheric magnetic field observations, they form a powerful data set that can be used to deduce the physical properties of the plasma and the magnetic field in the active region corona. This article describes some results from a highly successful campaig
ISSN:0002-8606
DOI:10.1029/90EO00328
年代:1991
数据来源: WILEY
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2. |
NSF's ambitious Arctic system program |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 42,
1991,
Page 450-450
Lynn Teo Simarski,
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摘要:
The Arctic is the least known of any region of the world, but a new National Science Foundation program called Arctic System Science (ARCSS) aims to change that. Climate models suggest that global change will be amplified at the Earth's poles, particularly in the Arctic. Increasing carbon dioxide could change the Arctic's temperature more than 12°, as opposed to the 2–3° increase projected at the equator—a compelling reason for scientists to get to know the region better.NSF's research effort is “a systematic, multidisciplinary approach to all the science in the region,” according to Ted De Laca, head of ARCSS. The purpose of this special endeavor of the Division of Polar Programs is not to measure global change per se, he says, but to promote basic research on how the Arctic
ISSN:0002-8606
DOI:10.1029/90EO00329
年代:1991
数据来源: WILEY
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3. |
Minnesota Geological Survey may close |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 42,
1991,
Page 451-451
Susan Bush,
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摘要:
The future of the Minnesota Geological Survey is up in the air until January 1992, when the state legislature reconvenes. On June 4, Governor Arne H. Carlson vetoed a line‐item of the 2‐year University of Minnesota budget that contains funding for the MGS. If funds are not restored by special legislative appropriation and approved by the governor during the spring of 1992, MGS will be abolished effective July 1992.The possibility of closing the survey reflects a financial decision, according to Robert A. Schroeder, assistant to the governor. It is not based on the usefulness of the survey's work. “The governor's objective with his line‐item vetoes was to control overall spending, not to target specific programs,” he said. Since MGS is university‐affiliated, it is funded under Minnesota's Higher Education bill, rather than as a state agency. Because of overspending in 1991, the state has had to cut back funds, and the university is one area hit by budget cuts. The university may still choose to fund the program and has the flexibility to reallocate funds within
ISSN:0002-8606
DOI:10.1029/EO072i042p00451-02
年代:1991
数据来源: WILEY
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4. |
Spring 1991 Meeting outstanding papers |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 42,
1991,
Page 452-452
Anonymous,
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摘要:
The Atmospheric Sciences Committee has presented Kaye Brubaker and Jichun Shi with Outstanding Student Paper awards for presentations given at the AGU 1991 Spring Meeting, held in Baltimore May 28–31.Brubaker's paper, “Precipitation Recycling Estimated from Atmospheric Data,” presented quantitative estimates of the contribution of locallyevaporated moisture to precipitation over several large continental regions. Recycled precipitation is defined as water that evaporates from the land surface of a specified region and falls again as precipitation within the region. Brubaker applied a control volume analysis based on a model proposed by B
ISSN:0002-8606
DOI:10.1029/EO072i042p00452-01
年代:1991
数据来源: WILEY
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5. |
Probing the Earth's strength: Can we measure small stress at high pressure? |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 42,
1991,
Page 453-454
Andreas Kronenberg,
Stephen Kirby,
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PDF (611KB)
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摘要:
Simulating the conditions and processes that occur in the Earth's deep interior has been a major goal of experimental geophysics since the 1920s. In particular, pioneers such as P. W. Bridgman, David Griggs, Hugh Heard, Mervyn Paterson, William Brace, and their colleagues sought to establish the basic relations between differential stresses and rock and mineral deformation under pressure‐temperature conditions that favor such inelastic processes as brittle fracture, frictional sliding, plastic deformation, and dynamic metamorphism. This work has been applied to diverse problems in the Earth sciences, including the physical nature of earth quake sources, the forces that drive and resist plate movement, deformation under partial‐melting conditions at the tops of mantle plumes, the flexure of the lithosphere, post‐glacial rebound, and the origin of the preferred orientation of minerals and the resultant seismic anisotropy and metamorphic tex
ISSN:0002-8606
DOI:10.1029/EO072i042p00453-01
年代:1991
数据来源: WILEY
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