An accurate new method of calculating absolute magnitudes and K-corrections applied to the Sloan filter set

We describe an accurate new method for determining absolute magnitudes, and hence also K-corrections, that is simpler than most previous methods, being based on a quadratic function of just one suitably chosen observed color. The method relies on the extensive and accurate new set of 129 empirical galaxy template spectral energy distributions from Brown et al. A key advantage of our method is that we can reliably estimate random errors in computed absolute magnitudes due to galaxy diversity, photometric error and redshift error. We derive K-corrections for the five Sloan Digital Sky Survey filters and provide parameter tables for use by the astronomical community. Using the New York Value-Added Galaxy Catalog, we compare our K-corrections with those from kcorrect. Our K-corrections produce absolute magnitudes that are generally in good agreement with kcorrect. Absolute griz magnitudes differ by less than 0.02 mag and those in the u band by ~0.04 mag. The evolution of rest-frame colors as a function of redshift is better behaved using our method, with relatively few galaxies being assigned anomalously red colors and a tight red sequence being observed across the whole 0.0 < z < 0.5 redshift range

Optimisation of a parallel ocean general circulation model

Abstract. This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing rou- tines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel e?ciency of the model is adversely a?ected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers

Ex-ante evaluation of Seasonal, Real Time and Move-on Closures

The Ministry of EL&I asked IMARES to do an ex ante evaluation of temporal / spatial closures based on effort and cod catches by the Dutch demersal, TR1

Geometrically stopped Markovian random growth processes and Pareto tails

Many empirical studies document power law behavior in size distributions of economic interest such as cities, firms, income, and wealth. One mechanism for generating such behavior combines independent and identically distributed Gaussian additive shocks to log-size with a geometric age distribution. We generalize this mechanism by allowing the shocks to be non-Gaussian (but light-tailed) and dependent upon a Markov state variable. Our main results provide sharp bounds on tail probabilities, a simple equation determining Pareto exponents, and comparative statics. We present two applications: we show that (i) the tails of the wealth distribution in a heterogeneous-agent dynamic general equilibrium model with idiosyncratic investment risk are Paretian, and (ii) a random growth model for the population dynamics of Japanese municipalities is consistent with the observed Pareto exponent but only after allowing for Markovian dynamics

Validating weather and climate models at small Rossby numbers: including a boundary layer

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Ideally, the validation of weather and climate models requires that the predictions remain close to an exact solution of the governing equations. The complexity of weather and climate models means that it is not possible to compute exact solutions except in trivial cases. However, in the limit of small Rossby number, the exact solution of the Euler equations can be shown to be close to that of a semi-geostrophic model, which can be computed. Previous studies have used the small-Rossby-number limit to validate numerical methods for a baroclinic wave without sub-grid physics. However, the method of coupling to the sub-grid physics plays an important role in the performance of weather and climate models. The aim of this article is thus to extend the previous studies to include a boundary-layer parametrization. We use a balanced model that includes a known boundary-layer parametrization, the semi-geotriptic model. We then demonstrate that the semi-geotriptic model is the appropriate small-Rossby-number limit of the solution of the Euler equations with the same boundary-layer representation. The semi-geotriptic model is then used to expose weaknesses in the numerical methods for coupling the boundary layer to the rest of the model

Urban Water Options Contracts - Rural to Urban Water Trade

Most urban centres across Australia are facing water shortages. In part, these water shortages are due to the variability of supply and demand caused by variable climatic conditions. Permanent supply augmentation to meet periodic water shortages can be costly. Water trade between rural and urban areas, through urban water options contracts, may be a less costly way to meet variability. Urban water options could be used to improve system reliability and may reduce costs by delaying investment and reducing the frequency and severity of water shortages. This paper investigates the potential to use urban water options contracts, and develops a methodology for evaluation.Resource /Energy Economics and Policy,

Parametrizing the Antarctic stable boundary layer: synthesizing models and observations

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The accurate representation of the stable boundary layer (SBL) is a key issue for weather prediction and climate models. The SBL exerts an important influence in controlling heat, moisture and momentum fluxes between the surface and the rest of the atmosphere. Some of the world's most stably stratified boundary layers develop on the Antarctic continent. Previous work investigating SBLs has tended to take either a purely observational or purely modelling-based approach. Here, a novel three-way methodology has been developed which uses observations from an Antarctic site, alongside large-eddy simulation (LES) and single-column model (SCM) techniques to examine a case-study. Reasonable agreement was generally achieved between the LES and observations. The choice of stability function is an important decision for column-based parametrizations of the SBL. Four schemes were tested in the SCM, providing persuasive evidence for the use of shorter-tailed stability functions. The LES data were also used to extract implied stability functions. These experiments reinforced the conclusion that shorter-tailed stability functions offered improved performance for the Antarctic SBL. This approach represents a powerful framework for verifying SCM and LES results against a range of insitu observations

Scientific, Technical and Economic Committee for Fisheries (STECF) - Report of the Working Group on Research Needs - Review of List of Surveys at Sea (Appendix XIV OF EU Commission Regulation N°1581/2004) with their Priorities (SGRN 07-01)

SGRN-07-01 was held on 12-16 February 2007 in Brussels. The report describes the operational prioritisation criteria for fisheries surveys at sea necessary for the compilation of a list of surveys at sea to be considered for co-funding by the new Data Collection Regulation (DCR). STECF expressed its opinion on the report during its the plenary meeting in April 2007.JRC.G.4-Maritime affair