Improving ENSO Simulations and Predictions Through Ocean State Estimation

Simulations and seasonal forecasts of tropical Pacific SST and subsurface fields that are based on the global Consortium for Estimating the Circulation and Climate of the Ocean (ECCO) ocean-state estimation procedure are investigated. As compared to similar results from a traditional ENSO simulation and forecast procedure, the hindcast of the constrained ocean state is significantly closer to observed surface and subsurface conditions. The skill of the 12-month lead SST forecast in the equatorial Pacific is comparable in both approaches. The optimization appears to have better skill in the SST anomaly correlations, suggesting that the initial ocean conditions and forcing corrections calculated by the ocean-state estimation do have a positive impact on the predictive skill. However, the optimized forecast skill is currently limited by the low quality of the statistical atmosphere. Progress is expected from optimizing a coupled model over a longer time interval with the coupling statistics being part of the control vector

ECONOMIC FEASIBILITY OF MARKETING MECHANICALLY HARVESTED ASPARAGUS IN THE FRESH MARKET

Lists results of sales tests where prepackaged mechanically harvested asparagus out sold traditional bunched asparagus 2.2 to 1.Consumer/Household Economics,

On the role of the optical phase and quantum coherence in high harmonic generation

In this work we analyze the role of the optical phase and coherence of the driving field in the process of high harmonic generation. We consider driving the process of high harmonic generation with incoherent classical and non-classical intense light fields, and show that harmonic radiation can be generated even in cases where the phase of the driving field is completely undetermined leading to vanishing mean electric field values. This implies that quantum optical coherence in the driving field is not necessary for generating high harmonic radiation, with the consequence that the emitted harmonic radiation in those cases do likewise not exhibit quantum optical coherence. We further show that the final quantum state of each harmonic is diagonal in the photon number basis, from which we conclude that the measurement of the high harmonic spectrum alone does not allow to infer on the coherence properties of the harmonic radiation.Comment: 5 page

Accuracy assessment of global barotropic ocean tide models

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109077/1/rog_stammeretal_tidereviewpaper_2014.pd

Theory of entanglement and measurement in high harmonic generation

Quantum information science and intense laser matter interaction are two apparently unrelated fields. However, the recent developments of the quantum optical description of the intense laser driven process of high harmonic generation allow to conceive new light engineering protocols. Here, we introduce the notion of quantum information theory to intense laser driven processes by providing the quantum mechanical description of measurement protocols for high harmonic generation in atoms. We explicitly evaluate conditioning experiments on individual optical field modes, and provide the corresponding quantum operation for coherent states. The associated positive operator-valued measures are obtained, and give rise to the quantum theory of measurement for the generation of high dimensional entangled states, and coherent state superposition with controllable non-classical features on the attosecond timescale.Comment: 6 page

Uncertainty quantification and numerical methods in charged particle radiation therapy

Radiation therapy is applied in approximately 50% of all cancer treatments. To eliminate the tumor without damaging organs in the vicinity, optimized treatment plans are determined. This requires the calculation of three-dimensional dose distributions in a heterogeneous volume with a spatial resolution of 2-3mm. Current planning techniques use multiple beams with optimized directions and energies to achieve the best possible dose distribution. Each dose calculation however requires the discretization of the six-dimensional phase space of the linear Boltzmann transport equation describing complex particle dynamics. Despite the complexity of the problem, dose calculation errors of less than 2% are clinically recommended and computation times cannot exceed a few minutes. Additionally, the treatment reality often differs from the computed plan due to various uncertainties, for example in patient positioning, the acquired CT image or the delineation of tumor and organs at risk. Therefore, it is essential to include uncertainties in the planning process to determine a robust treatment plan. This entails a realistic mathematical model of uncertainties, quantification of their effect on the dose distribution using appropriate propagation methods as well as a robust or probabilistic optimization of treatment parameters to account for these effects. Fast and accurate calculations of the dose distribution including predictions of uncertainties in the computed dose are thus crucial for the determination of robust treatment plans in radiation therapy. Monte Carlo methods are often used to solve transport problems, especially for applications that require high accuracy. In these cases, common non-intrusive uncertainty propagation strategies that involve repeated simulations of the problem at different points in the parameter space quickly become infeasible due to their long run-times. Quicker deterministic dose calculation methods allow for better incorporation of uncertainties, but often use strong simplifications or admit non-physical solutions and therefore cannot provide the required accuracy. This work is concerned with finding efficient mathematical solutions for three aspects of (robust) radiation therapy planning: 1. Efficient particle transport and dose calculations, 2. uncertainty modeling and propagation for radiation therapy, and 3. robust optimization of the treatment set-up