title: Solar wind fluctuations and the von Kármán–Howarth equations: The role of fourth-order correlations

authors: Oughton, Sean

subjects: interplanetary magnetic fields

abstract: The von Kármán-Howarth (vKH) hierarchy of equations relate the second-order correlations of the turbulent fluctuations to the third-order ones, the third-order to the fourth-order, and so on. We recently demonstrated [1] that for MHD, self-similar solutions to the vKH equations seem to require at least two independent similarity lengthscales (one for each Elsässer energy), so that compared to hydrodynamics a richer set of behaviors seems likely to ensue. Moreover, despite the well-known anisotropy of MHD turbulence with a mean magnetic field (B₀), the equation for the second-order correlation does not contain explicit dependence on B₀. We show that there is, however, implicit dependence on B₀ via the third-order correlations, which themselves have both explicit B₀-dependence and also their own implicit dependence through fourth-order correlations. Some subtleties and consequences of this implicit-explicit balance are summarized here. In addition, we present an analysis of simulation results showing that the evolution of turbulence can depend strongly on the initial fourth-order correlations of the system. This leads to considerable variation in the energy dissipation rates. Some associated consequences for MHD turbulence are discussed.

text: Solar wind fluctuations and the von Kármán–Howarth equations: The role of fourth-order correlations The von Kármán-Howarth (vKH) hierarchy of equations relate the second-order correlations of the turbulent fluctuations to the third-order ones, the third-order to the fourth-order, and so on. We recently demonstrated [1] that for MHD, self-similar solutions to the vKH equations seem to require at least two independent similarity lengthscales (one for each Elsässer energy), so that compared to hydrodynamics a richer set of behaviors seems likely to ensue. Moreover, despite the well-known anisotropy of MHD turbulence with a mean magnetic field (B₀), the equation for the second-order correlation does not contain explicit dependence on B₀. We show that there is, however, implicit dependence on B₀ via the third-order correlations, which themselves have both explicit B₀-dependence and also their own implicit dependence through fourth-order correlations. Some subtleties and consequences of this implicit-explicit balance are summarized here. In addition, we present an analysis of simulation results showing that the evolution of turbulence can depend strongly on the initial fourth-order correlations of the system. This leads to considerable variation in the energy dissipation rates. Some associated consequences for MHD turbulence are discussed.

year: 2013

title: I-O Psychology in Aotearoa, New Zealand: A world away?

authors: O’Driscoll, Michael P.

subjects: Psychology

abstract: Industrial-organizational psychology has had a fairly long history in this country, dating back to around the 1920s (Jamieson & Paterson, 1993). To a large extent the field developed initially within universities, although the focus of I-O psychologists’ activities in this country has always been very applied. Inclusion of I-O psychology in university curricula originally started at the University of Canterbury (in the south island) and then Massey University (in the north island); now two other universities (University of Auckland and University of Waikato, both in the north island) also provide training programs in the field. There are about a dozen academics in psychology departments who would consider themselves to be I-O psychologists, and a small handful in management or HRM departments. Clearly the number of academics specializing in this field is very small. Although this poses challenges for the development of I-O psychology in Aotearoa New Zealand, at the same time it helps communication among us.

text: I-O Psychology in Aotearoa, New Zealand: A world away? Industrial-organizational psychology has had a fairly long history in this country, dating back to around the 1920s (Jamieson & Paterson, 1993). To a large extent the field developed initially within universities, although the focus of I-O psychologists’ activities in this country has always been very applied. Inclusion of I-O psychology in university curricula originally started at the University of Canterbury (in the south island) and then Massey University (in the north island); now two other universities (University of Auckland and University of Waikato, both in the north island) also provide training programs in the field. There are about a dozen academics in psychology departments who would consider themselves to be I-O psychologists, and a small handful in management or HRM departments. Clearly the number of academics specializing in this field is very small. Although this poses challenges for the development of I-O psychology in Aotearoa New Zealand, at the same time it helps communication among us.

year: 2007

title: Incentivising change in the Lake Rotorua catchment

authors: Grayling, Anna

abstract: Anna Grayling is the Rotorua Lakes Business Manager for Bay of Plenty Regional Council. After completing a Bachelor of Law and a Bachelor of Sciences at the University of Waikato, Anna’s career began as an ecological consultant. Following this role, Anna spent five years in planning and policy for both the district and regional councils. For the last five years Anna has been dedicated to the Rotorua Te Arawa Lakes Programme. She is now the project lead for the Incentive Fund Development for land-use change in the Lake Rotorua catchment.
Alastair MacCormick has worked as a Lakes Restoration Officer with the Bay of Plenty Regional Council since 2007. His primary function has been the implementation of nutrient discharge limits under Rule 11. An experienced user of the Overseer nutrient budgeting software, and with broad knowledge of farming systems in the catchment, he also provides information and advice on the issues and complications associated with nutrient accounting.

text: Incentivising change in the Lake Rotorua catchment Anna Grayling is the Rotorua Lakes Business Manager for Bay of Plenty Regional Council. After completing a Bachelor of Law and a Bachelor of Sciences at the University of Waikato, Anna’s career began as an ecological consultant. Following this role, Anna spent five years in planning and policy for both the district and regional councils. For the last five years Anna has been dedicated to the Rotorua Te Arawa Lakes Programme. She is now the project lead for the Incentive Fund Development for land-use change in the Lake Rotorua catchment.
Alastair MacCormick has worked as a Lakes Restoration Officer with the Bay of Plenty Regional Council since 2007. His primary function has been the implementation of nutrient discharge limits under Rule 11. An experienced user of the Overseer nutrient budgeting software, and with broad knowledge of farming systems in the catchment, he also provides information and advice on the issues and complications associated with nutrient accounting.

year: 2013