The benefits of interdisciplinarity: residence time

The so-called residence time of a system is both an immensely useful and highly intuitive conception which provides a relevant timescale for processes. For example, the residence time of nutrients flowing into a pond would be the average ‘lifetime’ of the nutrients before being taking up by the pond creatures. If it is a small…

Interpolating Bathymetry to Unstructured Mesh

A few weeks (perhaps months) ago I introduced the side project that I am involved with (here) whereby our aim is to develop a hydrographic model for Apalachicola Bay, Fl. Today I wanted to provide an update for that project while also sharing some interesting problems that we’ve had to work around. To see the…

Sediment Traps: Historical Trends and the Promise of Inovation

[NB: The first entry in this series was published here, Introduction to Sediment Traps, which covers the motivation, use and issues of sediment traps.] Although validation of the data was lacking, sediment traps (or sedimentation traps as they were once called) were being used by the 1970s in the study of lakes (Davison et al., 1982;…

Philosophy Monday: On the Origin, Propagation and Cause of Variations

Darwin’s On the Origins of Species provided a vivid and practical mechanism to explain how variations within a species can be selected for. This mechanism became known as natural selection or, perhaps less accurately, survival of the fittest. Although Darwin’s natural selection mechanism was not novel—Malthus described a similar mechanism as actively limiting a population’s…

Markov Chain Monte Carlo: A Practical Introduction

Markov Chain Monte Carlo simulation sounds, admittedly, like a method better left to professional practitioners and the like; but please don’t let the esoteric name fool you. MCMC, as we like to call is, is a powerful yet deceptively simple technique that can be useful in problems ranging throughout science and engineering. Since this promises…

Spurious diapycnal mixing in z coordinate models

Introduction Diapycnal mixing is a natural process whereby water parcels of different temperature and/or salinity get mixed.  This process, as opposed to advection, is non-adiabatic (non-reversible) and is governed by diffusive mechanisms. The rate of diapycnal mixing is elevated in coastal waters relative to the open ocean and is responsible for the introduction of nutrients…

Philosophy Monday: Einstein v Newton

The source for the tension between Newton’s view of the universe and of Einstein’s stems from each person’s respective choice of axioms. Newton choose to take the most concrete axioms for his mechanics: absolute nature of space and time. These intuitive assumptions mark and define the whole of Newtonian mechanics since all the other definitions…