Southern Oscillation simulation in the OSU coupled upper ocean-atmosphere GCM     

Kenneth R Sperber  Sultan Hameed 《Climate Dynamics》1991,6(2):83-97

The Southern Oscillation is a major component in the interannual variations of global climate. The Oregon State University global climate model, with a dynamically interactive upper ocean, reproduces in qualitatively correct fashion some of the major characteristics of the Southern Oscillation. This model simulates the observed anti-correlation of annually averaged sea-level pressure (SLP) between the eastern Pacific and the Indonesian region, the primary atmospheric signal of the Southern Oscillation. In the composite of the simulated warm events positive sea-surface temperature (SST) anomalies expand eastward towards South America from the tropical western Pacific during the first half of the calendar year. The SST anomalies develop in conjunction with eastward mixed layer current anomalies in the tropical Pacific. In the late summer and early fall anomalously warm water near South America develops and moves westward to merge with the central Pacific anomalies. This lagged development in the eastern Pacific is analogous to the evolution of the 1982/83 and 1986/87 El Ninos. The temperature of the thermocline layer also increases, with the slope of the equatorial Pacific thermocline decreasing in response to the relaxation of the surface forcing. Enhanced precipitation occurs in the mid-Pacific while in the Indian and Australian monsoon regions a deficit occurs. The peak of the warm phase occurs in late northern fall/early winter, somewhat earlier than during observed El Ninos. The cold phase of the Southern Oscillation, enhancement of the zonal circulation, evolves in a fashion similar to the warm phase with the signs of the anomalies reversed, similar to observations. Occurrence of Southern Oscillation in this coarse resolution GCM indicates that high resolution ocean waves do not play a crucial role in the generation of this phenomenon as suggested by Pacific basin models. These results also show that ocean-atmosphere global climate models are useful tools for investigation of time dependent changes on the interannual timescale in addition to their hitherto accepted use for studying equilibrium properties of climate.  相似文献   

Integrated assessments of the impacts of climate change on natural resources   总被引：1，自引：0，他引：1  

Kenneth D. Frederick 《Climatic change》1994,28(1-2):1-14

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An equation of state for carbon dioxide valid from zero to extreme pressures   总被引：6，自引：0，他引：6  

S. Michael Sterner  Kenneth S. Pitzer 《Contributions to Mineralogy and Petrology》1994,117(4):362-374

A new form of equation of state is described with application to carbon dioxide from 215 K to T>2000 K and from zero pressure to more than 10⁵ bar (10 GPa). The equation was calibrated using properties predicted by existing formulations at low to moderate PT conditions, original experimental PVT data at higher pressures, corresponding states comparisons at higher temperatures and using shock compression data at still higher PTs. Extensive comparisons illustrating the correlation of our new EOS with available phase equilibria and volumetric data are provided. Fugacities of carbon dioxide at high pressures and temperatures predicted using our EOS are in agreement with mineral equilibria calculated from internally consistent thermodynamic data for minerals.  相似文献   

Rare earth element, 87Sr/86Sr,and 143Nd/144Nd compositions of Cenozoic orogenic dacites from Baja California,northwestern Mexico,and adjacent west Texas: evidence for the predominance of a subcrustal component     

Kenneth L. Cameron  Maryellen Cameron 《Contributions to Mineralogy and Petrology》1985,91(1):1-11

Dacitic lavas and ignimbrites were examined from seven localities that span the entire 700 km width of the mid- to late Cenozoic magmatic arc of northwestern Mexico and adjacent west Texas. These rocks have remarkably similar REE patterns that are parallel in the heavy REE and have modest negative Eu anomalies. Samples from three localities including Baja California, the Sierra Madre Occidental, and the Chihuahuan Basin and Range have initial ⁸⁷Sr/⁸⁶Sr between 0.7044 and 0.7050 and _Nd near 0.0±1.0. These dacites are isotopically similar to associated basalts, and they show no systematic isotopic variation that is correlated with age or composition of the basement. There is no evidence that magmas parental to these dacites interacted significantly with continental crust. Samples form three other localites in the Basin and Range vary in initial ⁸⁷Sr/⁸⁶Sr from 0.7051 to 0.7070 and _Nd from about -1 to –2. The composition of these rocks reflects contamination of the parental magmas by relatively small amounts of Precambrian crust. Collectively, the dacites of this study show much less isotopic variation than do Mesozoic granitoids (Farmer and DePaolo 1983) and late Cenozoic olivine tholeiites (Hart 1985) from similar transects of the western United States. The distinctive source region for the magmas parental to the Mexican dacites was relatively uniform isotopically, but it was enriched in LIL and HFS elements beneath the eastern Basin and Range.  相似文献   

Book reviews     

Boulding  Kenneth E.  Rosenberg  Norman J.  Harvey  L. D. Danny 《Climatic change》1985,7(4):461-466

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Hydrogeochemical exploration for Mississippi valley-type deposits, Arkansas, U.S.A.     

Kenneth F. Steele  T.F. Dilday III 《Journal of Geochemical Exploration》1985,23(1):71-79

Three areas located in northern Arkansas, U.S.A., representing differing host rock and mineralization, were selected to investigate the usefulness of hydrogeochemical exploration for Mississippi Valley-type Pb-Zn mineralization. Despite the geologic differences among the areas, there were no great differences in groundwater chemistry and threshold values. Anomalous Pb concentrations, and also anomalous Zn concentrations to a lesser extent, are useful in detecting the Pb-Zn mineralized areas; however, specific deposits could not be located. Because of the low threshold values (about 20 μg/1) for Pb and Zn, spring water must be utilized in order to avoid plumbing contamination.  相似文献   

The nursery role of seagrass meadows in the upper and lower reaches of the Chesapeake Bay     

Kenneth L. Heck  Timothy A. Thoman 《Estuaries and Coasts》1984,7(1):70-92

A two-year trawling and gill-netting study of vegetated and unvegetated bottoms near Parson’s Island, Maryland and near the mouth of the York River, Virginia was carried out to assess the nursery function of submerged vegetation for populations of fishes and decapod crustaceans in the Chesapeake Bay. Results revealed that vegetated bottoms supported substantially larger numbers of decapods, but not fishes, than unvegetated substrates. The lower Bay grassbed was an important nursery area for juvenile blue crabs, although neither of the grassbeds functioned as a nursery for commercially or recreationally valuable fishes. Our results suggest that: (1) further decreases in lower Bay Seagrass biomass would result in reduced numbers of adult blue crabs, but should not substantially affect populations of valuable fish species; (2) additional decreases in Upper Bay submerged vegetation should not produce dramatic change in the population sizes of either adult blue crabs or fishes.  相似文献   

The distribution and production of the hard clam,Mercenaria mercenaria,in Wassaw Sound,Georgia     

Walker  Randal L.  Tenore  Kenneth R. 《Estuaries and Coasts》1984,7(1):19-27

Estuaries and Coasts - Hard clams,Mercenaria mercenaria, occurred in four intertidal habitats in the outer, high salinity (18‰) region of Wassaw Sound, Georgia: small feeder creeks $$(\bar x...  相似文献   

Forecasting in the social and natural sciences: An overview and analysis of isomorphisms   总被引：1，自引：0，他引：1  

Kenneth C. Land  Stephen H. Schneider 《Climatic change》1987,11(1-2):7-31

This article identifies and analyzes several points of similarity in the structure and context of forecasting in the social and natural sciences. These include: the limits of identities or universal laws as a basis for forecasts; the corresponding need for simplifying parametric representations of one or more of the variables that enter into identities; various sources of uncertainty about parameterizations; intrinsic limitations on predictability or forecasting accuracy in large-scale systems; the need for sensitivity analyses of model responses to changes in exogenous variables and/or parametric structures; problems of model linkage; and the social (organizational and political) context of forecasts. Suggestions for future lines of inquiry are made in each case. Several of these are such that they can benefit from a sharing of experience and expertise across disciplinary lines.The research reported herein was supported in part by the IC² Institute, The University of Texas at Austin, and in part by National Science Foundation Grant Number SES-8411702. However, the opinions expressed in the paper are those of the authors and do not necessarily reflect those of the sponsoring organizations. We appreciate the advice and comments of Jesse H. Ausubel, Robert S. Chen, Judith Jacobsen, and Richard C. Rockwell on earlier versions of this paper.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

Explosive magma-water interactions: Thermodynamics,explosion mechanisms,and field studies   总被引：2，自引：2，他引：2  

Kenneth H. Wohletz 《Bulletin of Volcanology》1986,48(5):245-264

Physical analysis of explosive, magma-water interaction is complicated by several important controls: (1) the initial geometry and location of the contact between magma and water; (2) the process by which thermal energy is transferred from the magma to the water; (3) the degree to and manner by which the magma and water become intermingled prior to eruption; (4) the thermodynamic equation of state for mixtures of magma fragments and water; (5) the dynamic metastability of superheated water; and (6) the propagation of shock waves through the system. All of these controls can be analyzed while addressing aspects of tephra emplacement from the eruptive column by fallout, surge, and flow processes. An ideal thermodynamic treatment, in which the magma and external water are allowed to come to thermal equilibrium before explosive expansion, shows that the maximum system pressure and entropy are determined by the mass ratio of water and magma interacting. Explosive (thermodynamic) efficiency, measured by the ratio of maximum work potential to thermal energy of the magma, depends upon heat transfer from the pyroclasts to the vapor during the expansion stage. The adiabatic case, in which steam immediately separates from the tephra during ejection, produces lower efficiencies than does the isothermal case, in which heat is continually transferred from tephra to steam as it expands. Mechanisms by which thermal equilibrium between water and magma can be obtained require intimate mixing of the two. Interface instabilities of the Landau and Taylor type have been documented by experiments to cause fine-scale mixing prior to vapor explosion. In these cases, water is heated rapidly to a metastable state of superheat where vapor explosion occurs by spontaneous nucleation when a temperature limit is exceeded. Mixing may also be promoted by shock wave propagation. If the shock is of sufficient strength to break the magma into small pieces, thermal equilibrium and vapor production in its wake may drive the shock as a thermal detonation. Because these mechanisms of magma fragmentation allow calculation of grain size, vapor temperature and pressure, and pressure rise times, detailed emplacement models can be developed by critical field and laboratory analysis of the resulting tephra deposits. Deposits left by dense flows of tephra and wet steam as opposed to those left by dilute flows of dry steam and tephra show contrasts in median grain size, dispersal area, grain shape, grain surface chemistry, and bed form.  相似文献