scholarly journals Global ULF wave analysis of radial diffusion coefficients using a global MHD model for the 17 March 2015 storm

2016 ◽  
Vol 121 (7) ◽  
pp. 6196-6206 ◽  
Author(s):  
Zhao Li ◽  
Mary Hudson ◽  
Jan Paral ◽  
Michael Wiltberger ◽  
Drew Turner
Keyword(s):  
Diffusion Coefficients ◽  
Radial Diffusion ◽  
Wave Analysis ◽  
Ulf Wave ◽  
Mhd Model

scholarly journals ULF wave analysis and radial diffusion calculation using a global MHD model for the 17 March 2013 and 2015 storms

2017 ◽  
Vol 122 (7) ◽  
pp. 7353-7363 ◽  
Author(s):  
Zhao Li ◽  
Mary Hudson ◽  
Maulik Patel ◽  
Michael Wiltberger ◽  
Alex Boyd ◽  
...  
Keyword(s):  
Radial Diffusion ◽  
Wave Analysis ◽  
Ulf Wave ◽  
Diffusion Calculation ◽  
Mhd Model

ULF Wave Power During Geomagnetic Storms and Implications for Radial Diffusion Processes

2021 ◽  
Author(s):  
Jasmine Sandhu ◽  
Jonathan Rae ◽  
John Wygant ◽  
Aaron Breneman ◽  
Sheng Tian ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Geomagnetic Storms ◽  
Radial Diffusion ◽  
Ulf Waves ◽  
Wave Power ◽  
Outer Radiation Belt ◽  
Large Variability ◽  
Ulf Wave

<p>Ultra Low Frequency (ULF) waves drive radial diffusion of radiation belt electrons, where this process contributes to and, at times, dominates energisation, loss, and large scale transport of the outer radiation belt. In this study we quantify the changes and variability in ULF wave power during geomagnetic storms, through a statistical analysis of Van Allen Probes data for the time period spanning 2012 – 2019. The results show that global wave power enhancements occur during the main phase, and continue into the recovery phase of storms. Local time asymmetries show sources of ULF wave power are both external solar wind driving as well as internal sources from coupling with ring current ions and substorms.</p><p>The statistical analysis demonstrates that storm time ULF waves are able to access lower L values compared to pre-storm conditions, with enhancements observed within L = 4. We assess how magnetospheric compressions and cold plasma distributions shape how ULF wave power propagates through the magnetosphere. Results show that the Earthward displacement of the magnetopause is a key factor in the low L enhancements. Furthermore, the presence of plasmaspheric plumes during geomagnetic storms plays a crucial role in trapping ULF wave power, and contributes significantly to large storm time enhancements in ULF wave power.</p><p>The results have clear implications for enhanced radial diffusion of the outer radiation belt during geomagnetic storms. Estimates of storm time radial diffusion coefficients are derived from the ULF wave power observations, and compared to existing empirical models of radial diffusion coefficients. We show that current Kp-parameterised models, such as the Ozeke et al. [2014] model, do not fully capture the large variability in storm time radial diffusion coefficients or the extent of enhancements in the magnetic field diffusion coefficients.</p>

scholarly journals Analytic expressions for ULF wave radiation belt radial diffusion coefficients

2014 ◽  
Vol 119 (3) ◽  
pp. 1587-1605 ◽  
Author(s):  
Louis G. Ozeke ◽  
Ian R. Mann ◽  
Kyle R. Murphy ◽  
I. Jonathan Rae ◽  
David K. Milling
Keyword(s):  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Radial Diffusion ◽  
Wave Radiation ◽  
Ulf Wave ◽  
Analytic Expressions

scholarly journals ULF wave derived radiation belt radial diffusion coefficients

2012 ◽  
Vol 117 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Louis G. Ozeke ◽  
Ian R. Mann ◽  
Kyle R. Murphy ◽  
I. Jonathan Rae ◽  
David K. Milling ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Radial Diffusion ◽  
Ulf Wave

scholarly journals Electric and magnetic radial diffusion coefficients using the Van Allen probes data

2016 ◽  
Vol 121 (10) ◽  
pp. 9586-9607 ◽  
Author(s):  
Ashar F. Ali ◽  
David M. Malaspina ◽  
Scot R. Elkington ◽  
Allison N. Jaynes ◽  
Anthony A. Chan ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Radial Diffusion ◽  
Van Allen Probes

Radial diffusion coefficients database in the frame of SafeSpace project

2021 ◽  
Author(s):  
Christos Katsavrias ◽  
Ioannis A. Daglis ◽  
Afroditi Nasi ◽  
Constantinos Papadimitriou ◽  
Marina Georgiou
Keyword(s):  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Field Measurements ◽  
Radial Diffusion ◽  
Relativistic Electrons ◽  
Outer Radiation Belt ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
The Difference ◽  
Cycle 24

<p>Radial diffusion has been established as one of the most important mechanisms contributing the acceleration and loss of relativistic electrons in the outer radiation belt. Over the past few years efforts have been devoted to provide empirical relationships of radial diffusion coefficients (D<sub>LL</sub>) for radiation belt simulations yet several studies have suggested that the difference between the various models can be orders of magnitude different at high levels of geomagnetic activity as the observed D<sub>LL</sub> have been shown to be highly event-specific. In the frame of SafeSpace project we have used 12 years (2009 – 2020) of multi-point magnetic and electric field measurements from THEMIS A, D and E satellites to create a database of calculated D<sub>LL</sub>. In this work we present the first statistics on the evolution of D<sub>LL </sub>during the various phases of Solar cycle 24 with respect to the various solar wind parameters and geomagnetic indices.</p><p>This work has received funding from the European Union's Horizon 2020 research and innovation programme “SafeSpace” under grant agreement No 870437.</p>

scholarly journals Magnetic field power spectra and magnetic radial diffusion coefficients using CRRES magnetometer data

2015 ◽  
Vol 120 (2) ◽  
pp. 973-995 ◽  
Author(s):  
Ashar F. Ali ◽  
Scot R. Elkington ◽  
Weichao Tu ◽  
Louis G. Ozeke ◽  
Anthony A. Chan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Diffusion Coefficients ◽  
Power Spectra ◽  
Radial Diffusion ◽  
Magnetometer Data
Sign in / Sign up

Export Citation Format

Share Document