Friday, May 11, 2007

Meme to the policymakers look at the literature.

As we mentioned here the ecological communities of the biosphere, change rapidly to meet their changing levels of nutrients and energy. This is observable as shown by Ilya Prigorine and the Brusselator model of the BZ reaction.

A Belousov-Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator.

The reactions are theoretically important in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior. These reactions are far from equilibrium and remain so for a significant length of time. In this sense, they provide an interesting chemical model of nonequilibrium biological phenomena, and the mathematical model of the BZ reactions themselves are of theoretical interest.

Periodic variations of system properties in time, say by varying illumination in a light-sensitive Belousov-Zhabotinsky reaction (BZ) medium or another external forcing, leads to directed long-distance displacement of the spiral (Agladze et al. 1987; Davydov et al. 1988).ie resonant drift

An easy way to understand resonant drift is to consider a periodic series of short "shocks", say flashes of lights for the light-sensitive BZ medium. Due to stability and symmetry of a spiral wave, one such shock generically results in a displacement of the rotation centre of a spiral. If a series of shocks is timed so that each leads to a displacement in the same direction, this produces a drift.

This a skews the overlapped nitrogen/co2/hydrological cycle as the biosphere self organizes or corrects towards equilibrium, an objective it never meets due to a simple statement called Evolution ie homeostasis is never attained due to competition.

In an interesting review Codispoti shows that models and literature are far from equilibrium with the quantification of the oceanic nitrogen sink, due to perceptions of homeostasis in the paleo reconstructions.

Abstract. Measurements of the N2 produced by denitrification, a better understanding of non-canonical pathways for N2 production such as the anammox reaction, better appreciation of the multiple environments in which denitrification can occur (e.g. brine pockets in ice, within particles outside of suboxic water, etc.) suggest that it is unlikely that the oceanic denitrification rate is less than 400 TgNa−1. Because this sink term far exceeds present estimates for nitrogen fixation, the main source for oceanic fixed-N, there is a large apparent deficit ( 200 TgNa−1) in the oceanic fixed-N budget. The size of the deficit appears to conflict with apparent constraints of the atmospheric carbon dioxide and sedimentary 15N records that suggest homeostasis during the Holocene. In addition, the oceanic nitrate/phosphate ratio tends to be close to the canonical Redfield biological uptake ratio of 16 (by N and P atoms) which can be interpreted to indicatebthe existence of a powerful feed-back mechanism that forces the system towards a balance. The main point of this paper is that one cannot solve this conundrum by reducing the oceanic sink term. To do so would violate an avalanche of recent data on oceanic denitrification.

Biogeosciences, 4, 233–253, 2007
An oceanic fixed nitrogen sink exceeding 400 TgNa−1 vs the concept
of homeostasis in the fixed-nitrogen inventory
L. A. Codispoti


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