Erratum to: Impacts of rising air temperatures and emissions mitigation on electricity demand and supply in the United States: a multi-model comparison     

James McFarland  Yuyu Zhou  Leon Clarke  Patrick Sullivan  Jesse Colman  Wendy S. Jaglom  Michelle Colley  Pralit Patel  Jiyon Eom  Son H. Kim  G. Page Kyle  Peter Schultz  Boddu Venkatesh  Juanita Haydel  Charlotte Mack  Jared Creason 《Climatic change》2015,132(4):739-739

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The role of recharge and evapotranspiration as hydraulic drivers of ion concentrations in shallow groundwater on Everglades tree islands,Florida (USA)          下载免费PDF全文

Pamela L. Sullivan  René M. Price  Fernando Miralles‐Wilhelm  Mike S. Ross  Leonard J. Scinto  Thomas W. Dreschel  Fred H. Sklar  Eric Cline 《水文研究》2014,28(2):293-304

Recently, evapotranspiration has been hypothesized to promote the secondary formation of calcium carbonate year‐round on tree islands in the Everglades by influencing groundwater ions concentrations. However, the role of recharge and evapotranspiration as drivers of shallow groundwater ion accumulation has not been investigated. The goal of this study is to develop a hydrologic model that predicts the chloride concentrations of shallow tree island groundwater and to determine the influence of overlying biomass and underlying geologic material on these concentrations. Groundwater and surface water levels and chloride concentrations were monitored on eight constructed tree islands at the Loxahatchee Impoundment Landscape Assessment (LILA) from 2007 to 2010. The tree islands at LILA were constructed predominately of peat, or of peat and limestone, and were planted with saplings of native tree species in 2006 and 2007. The model predicted low shallow groundwater chloride concentrations when inputs of regional groundwater and evapotranspiration‐to‐recharge rates were elevated, while low evapotranspiration‐to‐recharge rates resulted in a substantial increase of the chloride concentrations of the shallow groundwater. Modeling results indicated that evapotranspiration typically exceeded recharge on the older tree islands and those with a limestone lithology, which resulted in greater inputs of regional groundwater. A sensitivity analysis indicated the shallow groundwater chloride concentrations were most sensitive to alterations in specific yield during the wet season and hydraulic conductivity in the dry season. In conclusion, the inputs of rainfall, underlying hydrologic properties of tree islands sediments and forest structure may explain the variation in ion concentration seen across Everglades tree islands. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

North Sea Foundation investigation techniques     

Richard A. Sullivan 《Marine Georesources & Geotechnology》2013,31(3):279-280

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Abundance and fractionation of Al,Fe and trace metals following tidal inundation of a tropical acid sulfate soil     

Scott G. Johnston  Edward D. Burton  Richard T. Bush  Annabelle F. Keene  Leigh A. Sullivan  Douglas Smith  Angus E. McElnea  Col R. Ahern  Bernard Powell 《Applied Geochemistry》2010

Tidal inundation was restored to a severely degraded tropical acid sulfate soil landscape and subsequent changes in the abundance and fractionation of Al, Fe and selected trace metals were investigated. After 5 a of regular tidal inundation there were large decreases in water-soluble and exchangeable Al fractions within former sulfuric horizons. This was strongly associated with decreased soil acidity and increases in pH, suggesting pH-dependent immobilisation of Al via precipitation as poorly soluble phases. The water-soluble fractions of Fe, Zn, Ni and Mn also decreased. However, there was substantial enrichment (2–5×) of the reactive Fe fraction (Fe_R; 1 M HCl extractable) near the soil surface, plus a closely corresponding enrichment of 1 M HCl extractable Cr, Zn, Ni and Mn. Surficial accumulations of Fe(III) minerals in the inter-tidal zone were poorly crystalline (up to 38% Fe_R) and comprised mainly of schwertmannite (Fe₈O₈(OH)₆SO₄) with minor quantities of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH). These Fe (III) mineral accumulations provide an effective substrate for the adsorption/co-precipitation and accumulation of trace metals. Arsenic displayed contrary behaviour to trace metals with peak concentrations (∼60 μg g⁻¹) near the redox minima. Changes in the abundance and fractionation of the various metals can be primarily explained by the shift in the geochemical regime from oxic–acidic to reducing-circumneutral conditions, combined with the enrichment of reactive Fe near the soil surface. Whilst increasing sequestration of trace metals via sulfidisation is likely to occur over the long-term, the current abundance of reactive Fe near the sediment–water interface favours a dynamic environment with respect to metals in the tidally inundated areas.  相似文献   

Statistical Variability of Dispersion in the Convective Boundary Layer: Ensembles of Simulations and Observations     

Jeffrey C. Weil  Peter P. Sullivan  Edward G. Patton  Chin-Hoh Moeng 《Boundary-Layer Meteorology》2012,145(1):185-210

A Lagrangian particle dispersion model (LPDM) driven by velocity fields from large-eddy simulations (LESs) is used to determine the mean and variability of plume dispersion in a highly convective planetary boundary layer (PBL). The total velocity of a “particle” is divided into resolved and unresolved or random (subfilter scale, SFS) velocities with the resolved component obtained from the LES and the SFS velocity from a Lagrangian stochastic model. This LPDM-LES model is used to obtain an ensemble of dispersion realizations for calculating the mean, root-mean-square (r.m.s.) deviation, and fluctuating fields of dispersion quantities. An ensemble of 30 realizations is generated for each of three source heights: surface, near-surface, and elevated. We compare the LPDM calculations with convection tank experiments and field observations to assess the realism of the results. The overall conclusion is that the LPDM-LES model produces a realistic range of dispersion realizations and statistical variability (i.e., r.m.s. deviations) that match observations in this highly convective PBL, while also matching the ensemble-mean properties. This is true for the plume height or trajectory, vertical dispersion, and the surface values of the crosswind-integrated concentration (CWIC), and their dependence on downstream distance. One exception is the crosswind dispersion for an elevated source, which is underestimated by the model. Other analyses that highlight important LPDM results include: (1) the plume meander and CWIC fluctuation intensity at the surface, (2) the applicability of a similarity theory for plume height from a surface source to only the very strong updraft plumes—not the mean height, and (3) the appropriate variation with distance of the mean surface CWIC and the lower bound of the CWIC realizations for a surface source.  相似文献   

Model histories: Narrative explanation in generative simulation modelling     

James D.A. Millington  David O’Sullivan  George L.W. Perry 《Geoforum》2012,43(6):1025-1034

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Application of in situ target-strength estimations in lakes: examples from rainbow-smelt surveys in Lakes Erie and Champlain   总被引：1，自引：0，他引：1  

Rudstam  L.G; Parker  S.L; Einhouse  D.W; Witzel  L.D; Warner  D.M; Stritzel  J.L; Parrish  D.L; Sullivan  P.J 《ICES Journal of Marine Science》2003,60(3):500-507

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δC and δN variations in Weddell Sea particulate organic matter     

G.H. Rau  C.W. Sullivan  L.I. Gordon 《Marine Chemistry》1991,35(1-4)

The δ¹³C and δ¹⁵N of particulate organic matter (POM) sampled from the Weddell Sea in 1986 and 1988 ranged from −30.4 to − 16.7%o and from −5.4 to +41.3%o, respectively. These large variations in POM δ¹³C and δ¹⁵N may reflect spatial/temporal changes in the concentrations and isotope abundances of CO₂(aq.) and NH₄⁺, respectively. Elevated isotope values were found exclusively in POM in or closely associated with sea ice, which may be the source of the ¹³C- and ¹⁵N-enriched sediments observed in this region.  相似文献   

Early diagenesis in rapidly accumulating sediments on the Alboran slope, ODP site 976     

Stefano M. Bernasconi  Philip A. Meyers  Gerard O&#;Sullivan 《Geo-Marine Letters》1999,18(3):209-214

 The oxidation and reduction that occur during early diagenesis of sediments has been studied in the interstitial waters of a rapidly accumulating sedimentary sequence from the Mediterranean margin of Spain. A series of reactions that are mediated by progressively lower free energy derived from oxidation of organic matter is evident in the sedimentary sequence. Iron and manganese are rapidly reduced. Phosphate and alkalinity maxima at a subbottom depth of 15 m indicate maximal organic matter degradation. Methane first appears at ∼20 m subbottom after sulfate is depleted, and its concentrations quickly climb. Received: 27 October 1997 / Revision received: 4 March 1998  相似文献   

A milky way search strategy for extraterrestial intelligence     

Woodruft T. Sullivan  Kenneth J. Mighell 《Icarus》1984,60(3):675-684

It is assumed that the density of sites of technical civilizations emitting suitable signals (whether purposeful or unintentional) is proportional to the stellar density at any location in our Galaxy, as modeled by Bahcall and Soneira (1980, Astrophys. J. Suppl. Ser.44, 73–110). A wide variety of possible radio luminosity functionsφ(L)for these civilizations is then assumed and for each the number of detectable signals per square degree over the sky is calculated. It has been found that most detectable signals occur at galactic latitudes of 10° or less and longitudes within 90° of the galactic center, a region which covers only 9% of the entire sky. This result holds for a wide range ofφ(L) types, including Gaussian distributions and power law functions with slopes less than 2.5, or any combination of these. The Milky Way is much less preffered, but still advantageous, for cases of steep power law functions (slopes greater than 2.5) or Gaussian functions with mean luminosities so low that any existing civilizations can only be detected at small distances(<0.5 kpc). The only cases where low galactic latitudes are not advantageous are (1) for frequencies of operation less than 600 MHz where the deleterious effects on signal-to-noise ratios of the natural galactic background emission become dominant, and (2) in searches for narrowband(<1 Hz) signals at frequencies less than 2 GHz where significant interstellar broadening of signals occurs over distances of? 10 kpc. Furthermore, all of the above results have broader applicability: they are equally valid for searches for any type of natural radio phenomenon if its probability of occurence is proportional to stellar density. Therefore, for a nontargeted search, a Milky Way strategy which concentrates on the inner galactic plane is preferred. The factor of 10 in time saved over an all-sky survey can then be used for, say, increased sensitivity or a survey of nearby galaxies. For a targeted search, rather than searching the nearestn solar-like stars, time is more profitably spent, for example, on the very nearest0.1n stars plus the next nearest0.9n stars which are also within 10° of the galactic plane. This picks up the Milky Way background while only sacrificing a factor of 2 in the average distance to the target stars.  相似文献