The Ekman vertical velocity in an enclosed β-plane ocean

The vertical flux beneath the surface boundary layer is determined by balancing the divergence induced in this layer by the prescribed wind stress and surface temperature with the divergence of an assumed geostrophic interior ftow. In this manner the equilibrium surface height over an enclosed basin is formulated as a boundary-value problem, the solution of which leads directly to the Ekman vertical velocity...

On the dynamical formulation of the large-scale momentum exchange between atmosphere and ocean

The vorticity equations for the vertically integrated momentum are derived for both the ocean and atmosphere, subject to the hydrostatic approximation, with the ocean\u27s surface treated as a material interface. The familiar wind-stress curl is the dominant momentum exchange mechanism for large- and synoptic-scale circulations, with the air-pressure torque on the sea surface becoming of comparable importance for motion scales of the order of 102 km. The effect of the divergence of the integrated mass flux is among the larger terms of the vorticity equation for all scales of transient motion considered

Alumina-supported triosmium clusters and ensembles: Characterization by high-resolution transmission electron microscopy

Structurally defined supported osmium clusters [HOs3(CO)10---O---Al3(CO)12] with the -OH groups of [gamma]-Al2O3. The supported clusters were heated to 200 [deg]C in argon and then reduced in hydrogen at 400 [deg]C, being characterized at different stages of the treatment by high-resolution transmission electron microscopy. After the sample had been heated to 200 [deg]C, scattering centers about 6 A in diameter were evident in the micrographs, their size being consistent with the expected geometry of three-atom ensembles of Os(II) complexes formed by cluster breakup. The ensembles were remarkably stable, and even prolonged exposure of the same area to the 100 keV electron beam caused neither disintegration nor agglomeration. After reduction of the osmium in hydrogen at 400 [deg]C, aggregates of similar size were observed. In contrast to the ensembles of Os(II) complexes, the aggregates seemed to disintegrate slowly under the impact of the electron beam. The difference in stability of the ensembles and the reduced osmium aggregates is attributed to the difference between the strong ionic bonds in the former sample and the weaker interaction between the reduced metal and the Al2O3 surface.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25063/1/0000494.pd

A review of the US Global Change Research Program and NASA's Mission to Planet Earth/Earth Observing System

This report reflects the results of a ten-day workshop convened at the Scripps Institution of Oceanography July 19-28, 1995. The workshop was convened as the first phase of a two part review of the U.S. Global Change Research Program (USGCRP). The workshop was organized to provide a review of the scientific foundations and progress to date in the USGCRP and an assessment of the implications of new scientific insights for future USGCRP and Mission to Planet Earth/Earth Observing System (MTPE/EOS) activities; a review of the role of NASA's MTPE/EOS program in the USGCRP observational strategy; a review of the EOS Data and Information System (EOSDIS) as a component of USGCRP data management activities; and an assessment of whether recent developments in the following areas lead to a need to readjust MTPE/EOS plans. Specific consideration was given to: proposed convergence of U.S. environmental satellite systems and programs, evolving international plans for Earth observation systems, advances in technology, and potential expansion of the role of the private sector. The present report summarizes the findings and recommendations developed by the Committee on Global Change Research on the basis of the presentations, background materials, working group deliberations, and plenary discussions of the workshop. In addition, the appendices include summaries prepared by the six working groups convened in the course of the workshop

The effective action of N=1 Calabi-Yau orientifolds

We determine the N=1 low energy effective action for compactifications of type IIB string theory on compact Calabi-Yau orientifolds in the presence of background fluxes from a Kaluza-Klein reduction. The analysis is performed for Calabi-Yau threefolds which admit an isometric and holomorphic involution. We explicitly compute the Kahler potential, the superpotential and the gauge kinetic functions and check the consistency with N=1 supergravity. We find a new class of no-scale Kahler potentials and show that their structure can be best understood in terms of a dual formulation where some of the chiral multiplets are replaced by linear multiplets. For O3- and O7-planes the scalar potential is expressed in terms of a superpotential while for O5- and O9-planes also a D-term and a massive linear multiplet can be present. The relation with the associated F-theory compactifications is briefly discussed.Comment: 40 pages, typos corrected, discussion of no-scale property improve

The effective action of Type IIA Calabi-Yau orientifolds

The N=1 effective action for generic type IIA Calabi-Yau orientifolds in the presence of background fluxes is computed from a Kaluza-Klein reduction. The Kahler potential, the gauge kinetic functions and the flux-induced superpotential are determined in terms of geometrical data of the Calabi-Yau orientifold and the background fluxes. The moduli space is found to be a Kahler subspace of the N=2 moduli space and shown to coincide with the moduli space arising in compactification of M-theory on a specific class of G_2 manifolds. The superpotential depends on all geometrical moduli and vanishes at leading order when background fluxes are turned off. The N=1 chiral coordinates linearize the appropriate instanton actions such that instanton effects can lead to holomorphic corrections of the superpotential. Mirror symmetry between type IIA and type IIB orientifolds is shown to hold at the level of the effective action in the large volume - large complex structure limit.Comment: 51 pages, typos correcte

Treating Solar Model Uncertainties: A Consistent Statistical Analysis of Solar Neutrino Models and Data

We describe how to consistently incorporate solar model uncertainties, along with experimental errors and correlations, when analyzing solar neutrino data to derive confidence limits on parameter space for proposed solutions of the solar neutrino problem. Our work resolves ambiguities and inconsistencies in the previous literature. As an application of our methods we calculate the masses and mixing angles allowed by the current data for the proposed MSW solution using both Bayesian and frequentist methods, allowing purely for solar model flux variations, to compare with previous work. We consider the effects of including metal diffusion in the solar models and also discuss implications for future experiments.Comment: 29 pages (incl figs), latex, 6 figures (appended as separate uuencoded file. To embed figures in text, uncomment 6 \epsfysize lines which appear before bibliography), CWRU-P5-94, CfPA-94-TTH-29, Fermilab-Pub-94/176-

Generalized N=1 Orientifold Compactifications and the Hitchin functionals

The four-dimensional N=1 supergravity theories arising in compactifications of type IIA and type IIB on generalized orientifold backgrounds with background fluxes are discussed. The Kahler potentials are derived for reductions on SU(3) structure orientifolds and shown to consist of the logarithm of the two Hitchin functionals. These are functions of even and odd forms parameterizing the geometry of the internal manifold, the B-field and the dilaton. The superpotentials induced by background fluxes and the non-Calabi-Yau geometry are determined by a reduction of the type IIA and type IIB fermionic actions on SU(3) and generalized SU(3) x SU(3) manifolds. Mirror spaces of Calabi-Yau orientifolds with electric and part of the magnetic NS-NS fluxes are conjectured to be certain SU(3) x SU(3) structure manifolds. Evidence for this identification is provided by comparing the generalized type IIA and type IIB superpotentials.Comment: 57 pages, references adde

Design and Simulated Performance of Calorimetry Systems for the ECCE Detector at the Electron Ion Collider

We describe the design and performance the calorimeter systems used in the ECCE detector design to achieve the overall performance specifications cost-effectively with careful consideration of appropriate technical and schedule risks. The calorimeter systems consist of three electromagnetic calorimeters, covering the combined pseudorapdity range from -3.7 to 3.8 and two hadronic calorimeters. Key calorimeter performances which include energy and position resolutions, reconstruction efficiency, and particle identification will be presented.Comment: 19 pages, 22 figures, 5 table