Occurrence and biological impacts of fishing gear and other marine debris in the Florida Keys   总被引：1，自引：0，他引：1  

Chiappone M  White A  Swanson DW  Miller SL 《Marine pollution bulletin》2002,44(7):597-604

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The economic effects of harmful algal blooms in the United States: Estimates,assessment issues,and information needs     

P.?HoaglandEmail author  D.?M.?Anderson  Y.?Kaoru  A.?W.?White 《Estuaries and Coasts》2002,25(4):819-837

During the last several decades, harmful algal bloom (HAB) events have been observed in more locations than ever before throughout the United States. Scientists have identified a larger number of algal species involved in HABs, more toxins have been uncovered, and more fisheries resources have been affected. Whether this apparent increase in HAB events is a real phenomenon or is the result of increased sampling and monitoring is a topic of intense discussions within the scientific community. We also have an inchoate understanding of the reasons for the apparent increase, particularly concerning the role of anthropogenic nutrient loadings as a causal factor. Whatever the reasons, virtually all coastal regions of the U.S. are now regarded as potentially subject to a wide variety and increased frequency of HABs. It is important to begin to understand the scale of the economic costs to society of such natural hazards. It is a common, but not yet widespread, practice for resource managers and scientists in many localities to develop rough estimates of the economic effects of HAB events in terms of lost sales in the relevant product or factor markets, expenditures for medical treatments, environmental monitoring and management budgets, or other types of costs. These estimates may be invoked in policy debates, often without concern about how they were developed. Although such estimates are not necessarily good measures of the true costs of HABs to society, they may help to measure the scale of losses and be suggestive of their distribution across political jurisdictions or industry sectors. With adequate interpretation, our thinking about appropriate policy responses may be guided by these estimates. Here we compile disparate estimates of the economic effects of HABs for events in the U.S. where such effects were measured during 1987–1992. We consider effects of four basic types: public health, commercial fisheries, recreation and tourism, and monitoring and management. We discuss many of the issues surrounding the nature of these estimates, their relevance as measures of the social costs of natural hazards, and their potential for comparability and aggregation into a national estimate.  相似文献   

Gas infall and stochastic star formation in galaxies in the local universe     

Guinevere Kauffmann  Timothy M. Heckman  Gabriella De Lucia  Jarle Brinchmann  Stéphane Charlot  Christy Tremonti  Simon D. M. White  Jon Brinkmann 《Monthly notices of the Royal Astronomical Society》2006,367(4):1394-1408

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Annual Conference of the Society of Risk Analysis     

Allen L. White 《The Professional geographer》1988,40(3):342-343

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Rotating neutron stars: an invariant comparison of approximate and numerical space–time models     

Emanuele Berti  Frances White  Asimina Maniopoulou  Marco Bruni 《Monthly notices of the Royal Astronomical Society》2005,358(3):923-938

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Solar observations with a millimeter-wavelength Array     

S. M. White  M. R. Kundu 《Solar physics》1992,141(2):347-369

Rapid developments in the techniques of interferometry at millimeter wavelengths now permit the use of telescope arrays similar to the Very Large Array at microwave wavelengths. These new arrays represent improvements of orders of magnitude in the spatial resolution and sensitivity of millimeter observations of the Sun, and will allow us to map the solar chromosphere at high spatial resolution and to study solar radio burst sources at millimeter wavelengths with high spatial and temporal resolution. Here we discuss the emission mechanisms at millimeter wavelengths and the phenomena which we expect will be the focus of such studies. We show that the flare observations study the most energetic electrons produced in solar flares, and can be used to constrain models for electron acceleration. We discuss the advantages and disadvantages of millimeter interferometry, and in particular focus on the use of and techniques for arrays of small numbers of telescopes.Paper presented at the 4th CESRA Workshop in Ouranopolis (Greece) 1991.  相似文献   

Spring and conduit sediments as storage reservoirs for heavy metals in karst aquifers     

D.?J.?VesperEmail author  W.?B.?White 《Environmental Geology》2004,45(4):481-493

Sediment samples were collected from six springs draining the karst aquifer at Fort Campbell, Kentucky/Tennessee. These were analyzed by ICP-MS following an extraction procedure that separates the metals into exchangeable, carbonate, oxide, organic and residual fractions. Aluminum and iron are primarily present in the residual fraction while manganese may be dominantly in either the oxide or carbonate fraction. The redox-sensitive metals (Fe and Mn) have the greatest fractional distribution in the spring with the thickest sediments. Trace metals detected include Cr, Cd, Ni, Pb, and Zn in the range of a few to 200 mg/kg. In Beaver Spring, nickel is distributed between the exchangeable, carbonate and organic fractions, while in Gordon Spring, nickel is largely residual. Chromium is almost entirely associated with the organic fraction in Beaver Spring while it is largely residual in Gordon Spring.  相似文献   

The Absolute Abundance of Iron in the Solar Corona     

White SM  Thomas RJ  Brosius JW  Kundu MR 《The Astrophysical journal》2000,534(2):L203-L206

We present a measurement of the abundance of Fe relative to H in the solar corona using a technique that differs from previous spectroscopic and solar wind measurements. Our method combines EUV line data from the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory with thermal bremsstrahlung radio data from the VLA. The coronal Fe abundance is derived by equating the thermal bremsstrahlung radio emission calculated from the EUV Fe line data to that observed with the VLA, treating the Fe/H abundance as the sole unknown. We apply this technique to a compact cool active region and find Fe&solm0;H=1.56x10-4, or about 4 times its value in the solar photosphere. Uncertainties in the CDS radiometric calibration, the VLA intensity measurements, the atomic parameters, and the assumptions made in the spectral analysis yield net uncertainties of approximately 20%. This result implies that low first ionization potential elements such as Fe are enhanced in the solar corona relative to photospheric values.  相似文献   

An example of radio and optical homologous flares     

K. P. White III  T. J. Janssens 《Solar physics》1970,11(2):291-298

Fokker (1967) has raised the question of whether the optical and radio homologies of flares are correlated. Two 2b flares occurring nearly 54 h apart (July 9 and 12, 1968) were observed at 29 wavelengths from H+4.00 Å to H–4.26 Å and at 10-cm radio. Adjacent pictures were spaced 0.295 Å and 2 sec apart. The time resolution of the radio traces was about 10 sec. Detailed comparison of the pictures showed near-perfect similarities in the two events. These similarities included flare shape, filament agitation, rising arch formation and surges with line-of-sight velocities nearly 200 km/ sec observed. Comparion of the microwave radio flux traces showed detailed similarities in the shapes and simultaneity of at least eight features.Research supported in part by the Atmospheric Sciences Section, National Science Foundation, NSF Grant GA-4184, while at Harvey Mudd College, Claremont, Calif.  相似文献   

Simulations of galaxy formation in a cosmological volume   总被引：1，自引：0，他引：1  

F.R. Pearce  A. Jenkins  C.S. Frenk  S.D.M. White  P.A. Thomas  H.M.P. Couchman  J.A. Peacock  G. Efstathiou 《Monthly notices of the Royal Astronomical Society》2001,326(2):649-666

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