Cruise report RV "Alkor" Cruise No. AL451

This report is based on preliminary data. Ventspils (Latvia). 01-02 March 2015 and 07-09 March 2015 Purpose of the cruise The original scientific goal of this cruise, conducted in the framework of the WGL/Pakt project ILWAO-II, was the investigation of the role of internal waves for basin-scale vertical mixing in the deep basins of the Baltic Sea. In agreement with IOW’s board, however, it was decided to devote a substantial part of the cruise time to the observation of one of the rare major saline inflow events that reached the central Baltic Sea exactly at the time of this cruise. In addition to the physical measurements, microbiological and chemical investigations were conducted, focusing on the role of methane-oxidizing bacteria in pelagic redoxclines

Triangular Gk-splines

In this paper a new approach is presented to construct piecewise polynomial G^k-surfaces of arbitrary topology and smoothness order k>= 1 of degree O(k). This approach generalizes some results presented in 1997 in CAGD and in 1999 at the St. Malo conference, respectively. In our construction only 4n polynomial patches are needed to fill an n-sided hole in a generalized C^k-(half)-boxspline surface. This is achieved by coalescing certain control points while at the same time maintaining a regular parametrization

A generic length-scale equation for geophysical turbulence models

A generalization of a class of differential length-scale equations typically used in second-order turbulence models for oceanic flows is suggested. Commonly used models, like the k-ε model and the Mellor-Yamada model, can be recovered as special cases of this generic model, and thus can be rationally compared. In addition, a method is proposed that yields a generalized framework for the calibration of the most frequently used class of differential length-scale equations. The generic model, calibrated with this method, exhibits a greater range of applicability than any of the traditional models. Stratified flows, plane mixing layers, and turbulence introduced by breaking surface waves are considered besides some classical test cases

Finite Element Analysis for Linear Elastic Solids Based on Subdivision Schemes

Finite element methods are used in various areas ranging from mechanical engineering to computer graphics and bio-medical applications. In engineering, a critical point is the gap between CAD and CAE. This gap results from different representations used for geometric design and physical simulation. We present two different approaches for using subdivision solids as the only representation for modeling, simulation and visualization. This has the advantage that no data must be converted between the CAD and CAE phases. The first approach is based on an adaptive and feature-preserving tetrahedral subdivision scheme. The second approach is based on Catmull-Clark subdivision solids