Heat transfer in inertial confinement fusion reactor systems (open access)

Heat transfer in inertial confinement fusion reactor systems

The short time and deposition distance for the energy from inertial fusion products results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. This paper presents an overview of the various inertial fusion reactor designs which attempt to reduce these peak power intensities and describes the heat transfer considerations for each design.
Date: April 23, 1980
Creator: Hovingh, J.
System: The UNT Digital Library
Partitioning between sediment and porewater of radiocesium from Chernobyl fallout (open access)

Partitioning between sediment and porewater of radiocesium from Chernobyl fallout

As part of a joint USA/USSR Environmental Agreement to determine the distribution and concentration of Chernobyl radioactivity in the northwest Black Sea area, the sediment from eight stations was collected and analyzed to assess the ability of sediment from the northwest Black Sea to adsorb radiocesium. Two methods were used to determine partitioning between liquid and solid phases; batch tests and porewater separation. In the batch test, Cs-137 tracer was added to mixtures of sediment and bottom water, with contact solutions ranging from 85 Bq/ml to 1760 Bq/ml. The distribution ratios (R{sub D}) for individual batch tests ranged from 390 to 1770 ml/g. Isotherms were linear for all cores and R{sub D} values calculated from the slopes of the isotherms ranged from 660 to 1660 ml/g. A second approach was used to determine the partitioning of Cs-137 between the porewater and the sediment under more natural conditions. The top 2 cm of two cores were sectioned and the sediment and the porewater were separated. In both samples the sediment contained significant amounts of Cs-137 and Cs-134 indicating the presence of fallout from the Chernobyl reactor accident. There was no cesium activity observed in the porewater at a minimum detectable level …
Date: April 23, 1991
Creator: Fuhrmann, M.; Pietrzak, R. (Brookhaven National Lab., Upton, NY (USA)); Neiheisel, J. & Dyer, R. (Environmental Protection Agency, Washington, DC (USA))
System: The UNT Digital Library
SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER (open access)

SALT FOG TEST OF SAM2X5 COATED STAINLESS STEEL CYLINDER

A salt fog test of an iron-based amorphous metal, SAM2X5, coated Type 316L stainless steel (SS316L) cylinder was made. The cylinder was 30-inch diameter by 88-inch long, and 3/8-inch thick. One end was welded shut with a SS316L end cap before coating. The body of the cylinder and the end cap were both coated. The cylinder was coated with SAM2X5 by the HVOF thermal spray process. The coating thickness was 0.015-inch to 0.019-inch thick. The cylinder was tested in a horizontal position. Also included in the test for reference purposes were five coupons (2-inch x 2-inch x 1/8-inch) of uncoated Type 1018 carbon steel (1018CS). The test used an abbreviated form of GM 9540P. Each cycle was 6 hours in duration and the cylinder and reference samples were exposed to a total of eight cycles. The cylinder was in relatively good condition after the test. Along the body of the cylinder only two pinpoint spot sized signs of rust were seen. The 1018CS reference specimens were extensively rusted.
Date: April 23, 2007
Creator: Aprigliano, L F; Rebak, R B; Choi, J; Lian, T & Day, S D
System: The UNT Digital Library
Landscape predictions from cosmological vacuum selection (open access)

Landscape predictions from cosmological vacuum selection

In Bousso-Polchinski models with hundreds of fluxes, we compute the effects of cosmological dynamics on the probability distribution of landscape vacua. Starting from generic initial conditions, we find that most fluxes are dynamically driven into a different and much narrower range of values than expected from landscape statistics alone. Hence, cosmological evolution will access only a tiny fraction of the vacua with small cosmological constant. This leads to a host of sharp predictions. Unlike other approaches to eternal inflation, the holographic measure employed here does not lead to staggering, an excessive spread of probabilities that would doom the string landscape as a solution to the cosmological constant problem.
Date: April 23, 2007
Creator: Bousso, Raphael; Bousso, Raphael & Yang, Sheng
System: The UNT Digital Library
Production of a sterile species: Quantum kinetics (open access)

Production of a sterile species: Quantum kinetics

Production of a sterile species is studied within an effective model of active-sterile neutrino mixing in a medium in thermal equilibrium. The quantum kinetic equations for the distribution functions and coherences are obtained from two independent methods: the effective action and the quantum master equation. The decoherence time scale for active-sterile oscillations is tau(dec)=2/Gamma(aa), but the evolution of the distribution functions is determined by the two different time scales associated with the damping rates of the quasiparticle modes in the medium: Gamma(1)=Gamma(aa)cos^2theta(m); Gamma(2)=Gamma(aa)sin^2theta(m) where Gamma(aa) is the interaction rate of the active species in the absence of mixing and theta(m) the mixing angle in the medium. These two time scales are widely different away from Mikheyev-Smirnov-Wolfenstein resonances and preclude the kinetic description of active-sterile production in terms of a simple rate equation. We give the complete set of quantum kinetic equations for the active and sterile populations and coherences and discuss in detail the various approximations. A generalization of the active-sterile transition probability in a medium is provided via the quantum master equation. We derive explicitly the usual quantum kinetic equations in terms of the"polarization vector" and show their equivalence to those obtained from the quantum master equation and effective …
Date: April 23, 2007
Creator: Ho, Chiu Man; Boyanovsky, D. & Ho, C.M.
System: The UNT Digital Library
3D Magnetotelluic characterization of the Coso GeothermalField (open access)

3D Magnetotelluic characterization of the Coso GeothermalField

Electrical resistivity may contribute to progress inunderstanding geothermal systems by imaging the geometry, bounds andcontrolling structures in existing production, and thereby perhapssuggesting new areas for field expansion. To these ends, a dense grid ofmagnetotelluric (MT) stations plus a single line of contiguous bipolearray profiling has been acquired over the east flank of the Cosogeothermal system. Acquiring good quality MT data in producing geothermalsystems is a challenge due to production related electromagnetic (EM)noise and, in the case of Coso, due to proximity of a regional DCintertie power transmission line. To achieve good results, a remotereference completely outside the influence of the dominant source of EMnoise must be established. Experimental results so far indicate thatemplacing a reference site in Amargosa Valley, NV, 65 miles from the DCintertie, isstill insufficient for noise cancellation much of the time.Even though the DC line EM fields are planar at this distance, theyremain coherent with the nonplanar fields in the Coso area hence remotereferencing produces incorrect responses. We have successfully unwrappedand applied MT times series from the permanent observatory at Parkfield,CA, and these appear adequate to suppress the interference of thecultural EM noise. The efficacy of this observatory is confirmed bycomparison to stations taken using an ultra-distant …
Date: April 23, 2007
Creator: Newman, Gregory A.; Hoversten, G. Michael; Wannamaker, Philip E. & Gasperikova, Erika
System: The UNT Digital Library
Light-Front Holography and AdS/QCD Correspondence (open access)

Light-Front Holography and AdS/QCD Correspondence

Light-Front Holography is a remarkable consequence of the correspondence between string theory in AdS space and conformal field theories in physical-space time. It allows string modes {Phi}(z) in the AdS fifth dimension to be precisely mapped to the light-front wavefunctions of hadrons in terms of a specific light-front impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron. This mapping was originally obtained by matching the exact expression for electromagnetic current matrix elements in AdS space with the corresponding exact expression for the current matrix element using light-front theory in physical space-time. More recently we have shown that one obtains the identical holographic mapping using matrix elements of the energy-momentum tensor, thus providing an important consistency test and verification of holographic mapping from AdS to physical observables defined on the light-front. The resulting light-front Schrodinger equations predicted from AdS/QCD give a good representation of the observed meson and baryon spectra and give excellent phenomenological predictions for amplitudes such as electromagnetic form factors and decay constants.
Date: April 23, 2008
Creator: Brodsky, Stanley J. & de Teramond, Guy F.
System: The UNT Digital Library
A QSAR for the Mutagenic Potencies of Twelve 2-Amino-trimethylimidazopyridine Isomers: Structural, Quantum Chemical,and Hydropathic Factors (open access)

A QSAR for the Mutagenic Potencies of Twelve 2-Amino-trimethylimidazopyridine Isomers: Structural, Quantum Chemical,and Hydropathic Factors

An isomeric series of heterocyclic amines related to one found in heated muscle meats was investigated for properties that predict their measured mutagenic potency. Eleven of the 12 possible 2-amino-trimethylimidazopyridine (TMIP) isomers were tested for mutagenic potency in the Ames/Salmonella test with bacterial strain TA98, and resulted in a 600-fold range in potency. Structural, quantum chemical and hydropathic data were calculated on the parent molecules and the corresponding nitrenium ions of all of the tested isomers to establish models for predicting the potency of the unknown isomer. The regression model accounting for the largest fraction of the total variance in mutagenic potency contains four predictor variables: dipole moment, a measure of the gap between amine LUMO and HOMO energies, percent hydrophilic surface, and energy of amine LUMO. The most important determinants of high mutagenic potency in these amines are: (1) a small dipole moment, (2) the combination of b-face ring fusion and N3-methyl group, and (3) a lower calculated energy of the {pi} electron system. Based on predicted potency from the average of five models, the isomer not yet synthesized and tested is expected to have a mutagenic potency of 0.84 revertants/{micro}g in test strain TA98.
Date: April 23, 2005
Creator: Knize, M G; Hatch, F T; Tanga, M J; Lau, E V & Colvin, M E
System: The UNT Digital Library
Diffraction Radiation by a Line Charge Moving Past a Comb: A Model of Radiation Losses in an Electron Ring Accelerator (open access)

Diffraction Radiation by a Line Charge Moving Past a Comb: A Model of Radiation Losses in an Electron Ring Accelerator

A calculation is given of the radiated energy loss from a charged rod which moves at constant speed past an infinite set of parallel semi-infinite conducting plates of infinitesimal thickness, with the rod taken parallel to and at a fixed distance from the plate edges. The problem is analyzed using the Wiener-Hopf technique, and the resulting formulas are evaluated analytically in the limits of high rod speed and low rod speed, and compared with numerical evaluation over the full range of speeds.
Date: April 23, 1970
Creator: Hazeltine, R. D.; Rosenbluth, M. N. & Sessler, A. M.
System: The UNT Digital Library
Dust Measurements in Tokamaks (open access)

Dust Measurements in Tokamaks

Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon …
Date: April 23, 2008
Creator: Rudakov, D.; Yu, J.; Boedo, J.; Hollmann, E.; Krasheninnikov, S.; Moyer, R. et al.
System: The UNT Digital Library
Permeability of generic repository rocks at simulated in situ conditions. [Comparison of Westerly granite and White Lake genissic granite] (open access)

Permeability of generic repository rocks at simulated in situ conditions. [Comparison of Westerly granite and White Lake genissic granite]

New laboratory data are reported on the effect of confining (lithostatic) pressure, pore-water pressure, and principal stress difference on permeability of Westerly granite and White Lake gneissic granite. Permeabilities as low as 10/sup -19/ cm/sup 2/ (10/sup -11/ D) have been measured successfully, using a transient technique. Principal strains, electrical conductivity, and compressional velocity are determined simultaneously. Applied loads on the 15-cm diameter by 28-cm long test sample are controlled automatically and all data are taken by a microcomputer. Results on the gneissic granite indicate permeabilities of 10/sup -18/ to 10/sup -19/ cm/sup 2/ that appear to be unaffected either by effective pressure or by stress. The granite yields permeabilities of 4x10/sup -16/ cm/sup 2/ that decrease by a factor of two with pressure and vary by a factor of two with stress. When compared to the initial value, compressional velocities increase by 4% and conductivity decreases by 50% as pressure is increased to 50 MPa in the gneissic granite. In granite, these become 3% and 58%, respectively. At pressure, loading of the granite of 0.5 of failure stress increases conductivity by about 20%.
Date: April 23, 1979
Creator: Heard, H.C.; Trimmer, D.; Duba, A. & Bonner, B.
System: The UNT Digital Library
The AGS Booster high frequency rf system (open access)

The AGS Booster high frequency rf system

A high level rf system, including a power amplifier and cavity, has been designed and built for the AGS Booster. It covers a frequency range of 2.4 to 4.2 MHz and will be used to accelerate high intensity protons. Low intensity polarized protons and heavy ions, to the 1.5 GeV level. A total accelerating voltage of up to 90 kV will be provided by two cavities, each having two gaps. The internally cross coupled, pushpull cavities are driven by an adjacently located power amplifier. In order to accommodate beam intensities up to 0.75 {times} 10{sup 13} protons per bunch, a low plate resistance power tetrode is used. The tube anode is magnetically coupled to one of the cavity's two parallel cells. The amplifier is a grounded cathode configuration driven by a remotely located solid-state amplifier. It has been tested in the laboratory at full gap voltage with satisfactory results. 5 refs., 2 figs., 1 tab.
Date: April 23, 1991
Creator: Sanders, R.T.; Cameron, P.; Eng, W.; Goldman, M.A.; Jablonski, E.; Kasha, D. et al.
System: The UNT Digital Library
Dual-laser flow cytometry of single mammalian cells. [Performance of low-power argon and high-power krypton laser system for quantitative analysis and sorting of cells] (open access)

Dual-laser flow cytometry of single mammalian cells. [Performance of low-power argon and high-power krypton laser system for quantitative analysis and sorting of cells]

An improved dual-laser flow cytometric system for quantitative analysis and sorting of mammalian cells has been developed using a low-power argon and high-power krypton laser as illumination sources, thus permitting the excitation of fluorescent dyes having absorption regions ranging from the ultraviolet to infrared. Cells stained in liquid suspension with fluorescent dyes enter a flow chamber where they intersect two spatially separated laser beams. Separate pairs of quartz beam-shaping optics focus each beam onto the cell stream. Electro-optical sensors measure fluorescence and light scatter from cells that are processed electronically and displayed as frequency distribution histograms. Cells also can be electronically separated and microscopically identified. The ease and versatility of operation designed into this system represent a marked technological improvement for dual-laser excited flow systems. Details of this instrument are described along with illustrative examples of cells stained with mithramycin and rhodamine and analyzed for DNA content, total protein, and nuclear and cytoplasmic diameter.
Date: April 23, 1978
Creator: Steinkamp, J.A.; Orlicky, D.J. & Crissman, H.A.
System: The UNT Digital Library
Real-time delay monitor for flow-system cell sorters (open access)

Real-time delay monitor for flow-system cell sorters

For optimum performance in cell sorting, it is critical to assure proper timing in the charging of droplets to be deflected. A method for determining the transit delay time in cell sorters has been devised and applied to daily operation in the Los Alamos sorter systems. This delay monitor relies on detection of either scattered or absorbed light from cells in the fluid stream near the point of droplet breakoff.
Date: April 23, 1978
Creator: Martin, J.C.; McLaughlin, S.R. & Hiebert, R.D.
System: The UNT Digital Library
Shock-Dispersed-Fuel Charges: Combustion in Chambers and Tunnels (open access)

Shock-Dispersed-Fuel Charges: Combustion in Chambers and Tunnels

None
Date: April 23, 2003
Creator: Neuwald, P; Reichenbach, H & Kuhl, A L
System: The UNT Digital Library
Astronomy Applications of Adaptive Optics at Lawrence Livermore National Laboratory (open access)

Astronomy Applications of Adaptive Optics at Lawrence Livermore National Laboratory

Astronomical applications of adaptive optics at Lawrence Livermore National Laboratory (LLNL) has a history that extends from 1984. The program started with the Lick Observatory Adaptive Optics system and has progressed through the years to lever-larger telescopes: Keck, and now the proposed CELT (California Extremely Large Telescope) 30m telescope. LLNL AO continues to be at the forefront of AO development and science.
Date: April 23, 2003
Creator: Bauman, B J & Gavel, D T
System: The UNT Digital Library
FROM THE ISR TO RHIC - MEASUREMENTS OF HARD-SCATTERING AND JETS USING INCLUSIVE SINGLE PARTICLE PRODUCTION AND 2-PARTICLE CORRELATIONS. (open access)

FROM THE ISR TO RHIC - MEASUREMENTS OF HARD-SCATTERING AND JETS USING INCLUSIVE SINGLE PARTICLE PRODUCTION AND 2-PARTICLE CORRELATIONS.

Hard scattering in p-p collisions, discovered at the CERN ISR in 1972 by the method of leading particles, proved that the partons of Deeply Inelastic Scattering strongly interacted with each other. Further ISR measurements utilizing inclusive single or pairs of hadrons established that high p{sub T} particles are produced from states with two roughly back-to-back jets which are the result of scattering of constituents of the nucleons as described by Quantum Chromodynamics (QCD), which was developed during the course of these measurements. These techniques, which are the only practical method to study hard-scattering and jet phenomena in Au+Au central collisions at RHIC energies, are reviewed, as an introduction to present RHIC measurements.
Date: April 23, 2005
Creator: Tannenbaum, M. J.
System: The UNT Digital Library
Thermodynamic Model of Afterburning in Explosions (open access)

Thermodynamic Model of Afterburning in Explosions

Thermodynamic states encountered during afterburning of explosion products gases in air were analyzed with the Cheetah code. Results are displayed in the form of Le Chatelier diagrams: the locus of states of specific internal energy versus temperature, for six different condensed explosives charges. Accuracy of the results was confirmed by comparing the fuel and products curves with the heats of detonation and combustion, and species composition as measured in bomb calorimeter experiments. Results were fit with analytic functions u = f ( T ) suitable for specifying the thermodynamic properties required for gas-dynamic models of afterburning in explosions.
Date: April 23, 2003
Creator: Kuhl, A L; Howard, M & Fried, L
System: The UNT Digital Library
Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array (open access)

Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array

Coincident {gamma} rays from a {sup 252}Cf source were measured using an array of six segmented high-purity germanium (HPGe) Clover detectors each enclosed by 16 bismuth-germanate (BGO) detectors. The detectors were arranged in a cubic pattern around a 1 {micro}Ci {sup 252}Cf source to cover a large solid angle for {gamma}-ray measurement with a reasonable reconstruction of the multiplicity. Neutron multiplicity was determined in certain cases by identifying the prompt {gamma} rays from individual fission fragment pairs. Multiplicity distributions from previous experiments and theoretical models were convolved with the response function of the array and compared to the present results. These results suggest a {gamma}-ray multiplicity spectrum broader than previous measurements and models, and provide no evidence of correlation with neutron multiplicity.
Date: April 23, 2008
Creator: Bleuel, D L; Bernstein, L A; Burke, J T; Gibelin, J; Heffner, M D; Mintz, J et al.
System: The UNT Digital Library
DEPOSITION VELOCITY ESTIMATION WITH THE GENII V2 SOFTWARE (open access)

DEPOSITION VELOCITY ESTIMATION WITH THE GENII V2 SOFTWARE

In 2010, the Department of Energy (DOE) Chief of Nuclear Safety and Office of Health, Safety and Security (HSS), with the support of industry experts in atmospheric sciences and accident dose consequences analysis, performed detailed analyses of the basis for the dry deposition velocity (DV) values used in the MACCS2 computer code. As a result of these analyses, DOE concluded that the historically used default DV values of 1 centimeter/second (cm/s) for unfiltered/unmitigated releases and 0.1 cm/s for filtered/mitigated releases may not be reasonably conservative for all DOE sites and accident scenarios. HSS recently issued Safety Bulletin 2011-02, Accident Analysis Parameter Update, recommending the use of the newly developed default DV, 0.1 cm/s for an unmitigated/unfiltered release. Alternatively site specific DV values can be developed using GENII version 2 (GENII v2) computer code. Key input parameters for calculating DV values include surface roughness, maximum wind speed for calm, particle size, particle density and meteorological data (wind speed and stability class). This paper will include reasonably conservative inputs, and a truncated parametric study. In lieu of the highly-conservative recommended DV value (0.1cm/s) for unmitigated/unfiltered release, GENII v2 has been used to justify estimated 95th percentile DV values. Also presented here are …
Date: April 23, 2012
Creator: Hutchins, H.
System: The UNT Digital Library
ENVIRONMENTAL REACTIVITY OF SOLID STATE HYDRIDE MATERIALS (open access)

ENVIRONMENTAL REACTIVITY OF SOLID STATE HYDRIDE MATERIALS

In searching for high gravimetric and volumetric density hydrogen storage systems, it is inevitable that higher energy density materials will be used. In order to make safe and commercially acceptable condensed phase hydrogen storage systems, it is important to understand quantitatively the risks involved in using and handling these materials and to develop appropriate mitigation strategies to handle potential material exposure events. A crucial aspect of the development of risk identification and mitigation strategies is the development of rigorous environmental reactivity testing standards and procedures. This will allow for the identification of potential risks and implementation of risk mitigation strategies. Modified testing procedures for shipping air and/or water sensitive materials, as codified by the United Nations, have been used to evaluate two potential hydrogen storage materials, 2LiBH{sub 4} {center_dot} MgH{sub 2} and NH{sub 3}BH{sub 3}. The modified U.N. procedures include identification of self-reactive substances, pyrophoric substances, and gas-emitting substances with water contact. The results of these tests for air and water contact sensitivity will be compared to the pure material components where appropriate (e.g. LiBH{sub 4} and MgH{sub 2}). The water contact tests are divided into two scenarios dependent on the hydride to water mole ratio and heat transport characteristics. …
Date: April 23, 2009
Creator: Gray, J & Donald Anton, D
System: The UNT Digital Library
FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS (open access)

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack <25% through wall' in 2002, was clearly shown not to be a crack. Additionally, examination of a new area immediately adjacent to other cracks along a vertical weld revealed three new cracks. It is not known when these new cracks formed as they could very well have been present in 2002 as well. Therefore, a total of twelve …
Date: April 23, 2009
Creator: Wiersma, B; James Elder, J; Rodney Vandekamp, R & Charles Mckeel, C
System: The UNT Digital Library
IMPLEMENTATION OF CHEMWARE HORIZON LIMS AT THE WSCF (WASTE SAMPLING AND CHARACTERIZATION) LABORATORY (open access)

IMPLEMENTATION OF CHEMWARE HORIZON LIMS AT THE WSCF (WASTE SAMPLING AND CHARACTERIZATION) LABORATORY

None
Date: April 23, 2009
Creator: TF, DALE
System: The UNT Digital Library
Seasonally Resolved Surface Water (delta)14C Variability in the Lombok Strait: A Coralline Perspective (open access)

Seasonally Resolved Surface Water (delta)14C Variability in the Lombok Strait: A Coralline Perspective

We have explored surface water mixing in the Lombok Strait through a {approx}bimonthly resolved surface water {Delta}{sup 14}C time-series reconstructed from a coral in the Lombok Strait that spans 1937 through 1990. The prebomb surface water {Delta}{sup 14}C average is -60.5{per_thousand} and individual samples range from -72{per_thousand} to 134{per_thousand}. The annual average post-bomb maximum occurs in 1973 and is 122{per_thousand}. The timing of the post-bomb maximum is consistent with a primary subtropical source for the surface waters in the Indonesian Seas. During the post-bomb period the coral records regular seasonal cycles of 5-20{per_thousand}. Seasonal high {Delta}{sup 14}C occur during March-May (warm, low salinity), and low {Delta}{sup 14}C occur in September (cool, higher salinity). The {Delta}{sup 14}C seasonality is coherent and in phase with the seasonal {Delta}{sup 14}C cycle observed in Makassar Strait. We estimate the influence of high {Delta}{sup 14}C Makassar Strait (North Pacific) water flowing through the Lombok Strait using a two endmember mixing model and the seasonal extremes observed at the two sites. The percentage of Makassar Strait water varies between 16 and 70%, and between 1955 and 1990 it averages 40%. During La Nina events there is a higher percentage of Makassar Strait (high {Delta}{sup 14}C) water …
Date: April 23, 2008
Creator: Guilderson, T. P.; Fallon, S. J.; Moore, M. D.; Schrag, D. P. & Charles, C. D.
System: The UNT Digital Library