The occurrence and toxicity of herbicides in reef building corals     

Peter W Glynn  L.S Howard  Eugene Corcoran  Ana D Freay 《Marine pollution bulletin》1984,15(10):370-374

Herbicide residues including 2,4-D and 2,4,5-T have been detected in the tissues of corals subject to massive mortality in the Gulf of Chiriquí, Panamá. Tolerance tests conducted using Pocillopora damicornis demonstrated a toxic effect of a commercial herbicide (incorporating 2,4-D) on this coral.  相似文献   

Mars: Subsurface properties from observed longitudinal variation of the 3.5-mm brightness temperature     

Eugene E. Epstein  Bryan H. Andrew  Frank H. Briggs  Bruce M. Jakosky  Frank D. Palluconi 《Icarus》1983,56(3):465-475

Measurements at 3.5 mm of the disk-average brightness temperature of Mars during the 1978 opposition can be represented by (The errors cited are from the internal scatter; the estimated absolute calibration uncertainty is 3%.) This longitudinal variation must be taken into account if Mars is to be used as a calibration source at millimeter wavelengths. The total range of the 3.5-mm variation is three to four times larger than both the 2.8-cm and 20-μm variations. This unexpected result can possibly be explained by subsurface scattering from rocks ?1.5-cm radius.  相似文献   

Space, citizenship, and the right to the city: A brief overview     

Eugene J. McCann 《GeoJournal》2002,58(2-3):77-79

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Post-glacial diatom and geochemical records of ecological status and water level changes of Lake Vorota,Western Beringia     

Firsova  Alena D.  Chebykin  Eugene P.  Kopyrina  Liubov I.  Rodionova  Elena V.  Chensky  Dmitry A.  Gubin  Nikita A.  Panov  Vsevolod S.  Pogodaeva  Tatyana V.  Bukin  Yurij S.  Suturin  Alexandr N.  Likhoshway  Yelena V. 《Journal of Paleolimnology》2021,66(4):407-437

Journal of Paleolimnology - In this study, radiocarbon-dated geochemical and diatom records from Lake Vorota located within the informal meteorological ‘pole of cold’ of the northern...  相似文献   

Broadband submillimeter measurements of the full Moon center brightness temperature and application to a lunar eclipse     

Juan R. Pardo  Eugene Serabyn 《Icarus》2005,178(1):19-26

We report on observations of the full Moon brightness temperature covering the frequency range of 300-950 GHz, and also on observations of the lunar eclipse of July 16, 2000, though only covering the frequency range of 165-365 GHz due to poor atmospheric transmission at higher frequencies. All observations were performed from the summit of Mauna Kea (HI) using a Fourier Transform Spectrometer mounted on the Caltech Submillimeter Observatory and supplemented by measurements of the atmospheric opacity using a 183 GHz Water Vapor Monitor. The telescope was pointed to the center of the lunar disk (with a footprint of ∼45-15 km on the Moon at 300 through 900 GHz). In order to obtain the correct values of the Moon brightness temperatures at all frequencies we carefully corrected for the atmospheric absorption, which varies across the submillimeter domain. This correction is fully described. The measured pre-eclipse brightness temperature is around 337 K in the 165-365 GHz range. This temperature slightly increases with frequency to reach ∼353 K at 950 GHz, according to previous broader band data. The magnitude of the temperature drop observed during the eclipse at 265 GHz (central frequency of the band covered) was about ∼70 K, in very good agreement with previous millimeter-wave measurements of other lunar eclipses. We detected, in addition, a clear frequency trend in the temperature drop that has been compared to a thermal and microwave emission model of the lunar regolith, with the result of a good match of the relative flux drop at different frequencies between model and measurements.  相似文献   

A critical examination of the random displacement model of turbulent dispersion     

John D. Wilson  Eugene Yee 《Boundary-Layer Meteorology》2007,125(3):399-416

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The importance of the geophysical context in statistical evaluations of climate reconstruction procedures     

Caspar M. Ammann  Eugene R. Wahl 《Climatic change》2007,85(1-2):71-88

A portion of the debate about climate reconstructions of the past millennium, and in particular about the well-known Mann-Bradley-Hughes (“MBH” 1998, 1999) reconstructions, has become disconnected from the goal of understanding natural climate variability. Here, we reflect on what can be learned from recent scientific exchanges and identify important challenges that remain to be addressed openly and productively by the community. One challenge arises from the real, underlying trend in temperatures during the instrumental period. This trend can affect regression-based reconstruction performance in cases where the calibration period does not appropriately cover the range of conditions encountered during the reconstruction. However, because it is tied to a unique spatial pattern driven by change in radiative balance, the trend cannot simply be removed in the method of climate field reconstruction used by MBH on the statistical argument of preserving degrees of freedom. More appropriately, the influence from the trend can be taken into account in some methods of significance testing. We illustrate these considerations as they apply to the MBH reconstruction and show that it remains robust back to AD 1450, and given other empirical information also back to AD 1000. However, there is now a need to move beyond hemispheric average temperatures and to focus instead on resolving climate variability at the socially more relevant regional scale.  相似文献   

Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence   总被引：1，自引：1，他引：1  

Eugene R. Wahl  Caspar M. Ammann 《Climatic change》2007,85(1-2):33-69

The Mann et al. (1998) Northern Hemisphere annual temperature reconstruction over 1400–1980 is examined in light of recent criticisms concerning the nature and processing of included climate proxy data. A systematic sequence of analyses is presented that examine issues concerning the proxy evidence, utilizing both indirect analyses via exclusion of proxies and processing steps subject to criticism, and direct analyses of principal component (PC) processing methods in question. Altogether new reconstructions over 1400–1980 are developed in both the indirect and direct analyses, which demonstrate that the Mann et al. reconstruction is robust against the proxy-based criticisms addressed. In particular, reconstructed hemispheric temperatures are demonstrated to be largely unaffected by the use or non-use of PCs to summarize proxy evidence from the data-rich North American region. When proxy PCs are employed, neither the time period used to “center” the data before PC calculation nor the way the PC calculations are performed significantly affects the results, as long as the full extent of the climate information actually in the proxy data is represented by the PC time series. Clear convergence of the resulting climate reconstructions is a strong indicator for achieving this criterion. Also, recent “corrections” to the Mann et al. reconstruction that suggest 15th century temperatures could have been as high as those of the late-20th century are shown to be without statistical and climatological merit. Our examination does suggest that a slight modification to the original Mann et al. reconstruction is justifiable for the first half of the 15th century (∼+0.05^∘), which leaves entirely unaltered the primary conclusion of Mann et al. (as well as many other reconstructions) that both the 20th century upward trend and high late-20th century hemispheric surface temperatures are anomalous over at least the last 600 years. Our results are also used to evaluate the separate criticism of reduced amplitude in the Mann et al. reconstructions over significant portions of 1400–1900, in relation to some other climate reconstructions and model-based examinations. We find that, from the perspective of the proxy data themselves, such losses probably exist, but they may be smaller than those reported in other recent work. The National Center for Atmospheric Research is sponsored by the National Science Foundation, USA. The authors contributed equally to the development of the research presented.  相似文献   

Extension of a fluctuating plume model of tracer dispersion to a sheared boundary layer and to a large array of obstacles     

Ralph M. Gailis  Alexander Hill  Eugene Yee  Trevor Hilderman 《Boundary-Layer Meteorology》2007,122(3):577-607

Fluctuating plume models provide a useful conceptual paradigm in the understanding of plume dispersion in a turbulent flow. In particular, these models have enabled analytical predictions of higher-order concentration moments, and the form of the one-point concentration probability density function (PDF). In this paper, we extend the traditional formalism of these models, grounded in the theory of homogeneous and isotropic turbulent flow, to two cases: namely, a simple sheared boundary layer and a large array of regular obstacles. Some very high-resolution measurements of plume dispersion in a water channel, obtained using laser-induced fluorescence (LIF) line-scan techniques are utilised. These data enable us to extract time series of plume centroid position (plume meander) and dispersion in the relative frame of reference in unprecedented detail. Consequently, experimentally extracted PDFs are able to be directly compared with various theoretical forms proposed in the literature. This includes the PDF of plume centroid motion, the PDF of concentration in the relative frame, and a variety of concentration moments in the absolute and relative frames of reference. The analysis confirms the accuracy of some previously proposed functional forms of model components used in fluctuating plume models, as well as suggesting some new forms necessary to deal with the complex boundary conditions in the spatial domain.  相似文献   

MINERALOGICAL AND CHEMICAL RESEARCHES ON L-CHONDRITES: GIRGENTI     

G. R. Levi-Donati  Eugene Jarosewich 《Meteoritics & planetary science》1972,7(2):109-125

A mineralogical and chemical analysis has been performed on the largest mass (8750 g) of the Girgenti, Italy, meteorite, from the collection of the Smithsonian Institution, Washington, D.C. The mineralogical composition is olivine, Fa_24–25; hypersthene, Fs_{21 –22}; plagioclase, An₁₂; maskelynite; whitlockite; nickel-iron; troilite; chromite and ilmenite. Girgenti is a severly metamorphosed stone, whose total iron content (23.5%) is somewhat higher than the average for hypersthene chondrites.  相似文献