title: The diffusion approximation versus the telegraph equation for modeling solar energetic particle transport with adiabatic focusing. I. isotropic pitch-angle scattering

authors: Effenberger, Frederic

subjects: cosmic rays

abstract: The diffusion approximation to the Fokker-Planck equation is commonly used to model the transport of solar energetic particles in interplanetary space. In this study, we present exact analytical predictions of a higher order telegraph approximation for particle transport and compare them with the corresponding predictions of the diffusion approximation and numerical solutions of the full Fokker-Planck equation. We specifically investigate the role of the adiabatic focusing effect of a spatially varying magnetic field on an evolving particle distribution. Comparison of the analytical and numerical results shows that the telegraph approximation reproduces the particle intensity profiles much more accurately than does the diffusion approximation, especially when the focusing is strong. However, the telegraph approximation appears to offer no significant advantage over the diffusion approximation for calculating the particle anisotropy. The telegraph approximation can be a useful tool for describing both diffusive and wave-like aspects of the cosmic-ray transport.

text: The diffusion approximation versus the telegraph equation for modeling solar energetic particle transport with adiabatic focusing. I. isotropic pitch-angle scattering The diffusion approximation to the Fokker-Planck equation is commonly used to model the transport of solar energetic particles in interplanetary space. In this study, we present exact analytical predictions of a higher order telegraph approximation for particle transport and compare them with the corresponding predictions of the diffusion approximation and numerical solutions of the full Fokker-Planck equation. We specifically investigate the role of the adiabatic focusing effect of a spatially varying magnetic field on an evolving particle distribution. Comparison of the analytical and numerical results shows that the telegraph approximation reproduces the particle intensity profiles much more accurately than does the diffusion approximation, especially when the focusing is strong. However, the telegraph approximation appears to offer no significant advantage over the diffusion approximation for calculating the particle anisotropy. The telegraph approximation can be a useful tool for describing both diffusive and wave-like aspects of the cosmic-ray transport.

year: 2014

title: News from members: New Zealand

authors: Balks, Megan R.

subjects: New Zealand

abstract: This year we are celebrating 50 years since the first soil/ permafrost scientific expedition in the Ross Sea Region of Antarctica. It was undertaken by Prof. John D. McCraw and Dr Graeme G. Claridge. They set off from Scott Base on the Massey Fergusson tractors that Sir Edmund Hillary took to the South Pole in 1957/58 and drove to New Harbour, from which they travelled on foot for several weeks exploring the Taylor Valley and adjacent areas. Graeme Claridge went on to become an expert on Antarctic soil chemistry and, with Iain Campbell, authored the most authoritative book available on the soils of Antarctica. Both McCraw and Claridge are fit and well - (permafrost and cryosol research must be good for you) and we will be holding a celebration to mark their original journey in November this year.

text: News from members: New Zealand This year we are celebrating 50 years since the first soil/ permafrost scientific expedition in the Ross Sea Region of Antarctica. It was undertaken by Prof. John D. McCraw and Dr Graeme G. Claridge. They set off from Scott Base on the Massey Fergusson tractors that Sir Edmund Hillary took to the South Pole in 1957/58 and drove to New Harbour, from which they travelled on foot for several weeks exploring the Taylor Valley and adjacent areas. Graeme Claridge went on to become an expert on Antarctic soil chemistry and, with Iain Campbell, authored the most authoritative book available on the soils of Antarctica. Both McCraw and Claridge are fit and well - (permafrost and cryosol research must be good for you) and we will be holding a celebration to mark their original journey in November this year.

year: 2009

title: The development of guidelines for indigenous research ethics in Aotearoa/New Zealand.

authors: Hudson, Maui

abstract: The development of Indigenous frameworks for research ethics has been a key component of progressing Indigenous aspirations for research around the world. They have provided a focal point for challenging approaches to research that prioritise non-Indigenous methods and values, and allow non-Indigenous researchers to claim expert status over Indigenous peoples, places and knowledges. The theme of self-determination underpins contemporary approaches to Indigenous development and the repositioning of state-Indigenous nation relationships. This paper describes the background, development, and implementation by Māori communities and researchers of an Indigenous ethical framework in Aotearoa/New Zealand.

text: The development of guidelines for indigenous research ethics in Aotearoa/New Zealand. The development of Indigenous frameworks for research ethics has been a key component of progressing Indigenous aspirations for research around the world. They have provided a focal point for challenging approaches to research that prioritise non-Indigenous methods and values, and allow non-Indigenous researchers to claim expert status over Indigenous peoples, places and knowledges. The theme of self-determination underpins contemporary approaches to Indigenous development and the repositioning of state-Indigenous nation relationships. This paper describes the background, development, and implementation by Māori communities and researchers of an Indigenous ethical framework in Aotearoa/New Zealand.

year: 2016