A prediction model for the global distribution of whistler chorus wave amplitude developed separately for two latitudinal zones. Issue 4 (22nd April 2015)

• Record Type: Journal Article
• Authors: Kim, Jin‐Hee; Lee, Dae‐Young; Cho, Jung‐Hee; Shin, Dae‐Kyu; Kim, Kyung‐Chan; Li, Wen; Kim, Thomas K.
• Is Part Of: Journal of geophysical research. Volume 120:Issue 4(2015:Apr.)
• Page Start: 2819
• Page End: 2837
• Publication Date: 2015-04-22
• Subjects: Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2014JA020900
• Languages: English
• ISSNs: 2169-9380

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Whistler mode chorus waves are considered to play a central role in accelerating and scattering electrons in the outer radiation belt. While in situ measurements are usually limited to the trajectories of a small number of satellites, rigorous theoretical modeling requires a global distribution of chorus wave characteristics. In the present work, by using a large database of chorus wave observations made on the Time History of Events and Macroscale Interactions during Substorms satellites for about 5 years, we develop prediction models for a global distribution of chorus amplitudes. The development is based on two main components: (a) the temporal dependence of average chorus amplitudes determined by correlating with the preceding solar wind and geomagnetic conditions as represented by the interplanetary magnetic field (IMF) <italic>B</italic><sub>z</sub> and <italic>AE</italic> index and (b) the determination of spatial distribution pattern of chorus amplitudes, specifically, the profiles in <italic>L</italic> in all 2 h magnetic local time zones, which are categorized by activity levels of either the IMF <italic>B<sub>z</sub></italic> or <italic>AE</italic> index. Two separate models are developed: one based only on the IMF <italic>B<sub>z</sub></italic> and the other based only on <italic>AE</italic>. Both models predict chorus amplitudes for two different latitudinal zones separately: |magnetic latitude (MLAT)| < 10°, and |MLAT| = 10°–25°. The model performance is measured by the coefficient of determination <italic>R</italic><sup>2</sup> and the rank‐order correlation coefficient (ROCC) between the observations and model prediction results. When tested for a new data interval of ~1.5 years, the <italic>AE</italic>‐based model works slightly better than the IMF <italic>B</italic><sub>z</sub>‐based model: for the <italic>AE</italic>‐based model, the mean <italic>R</italic><sup>2</sup> and ROCC values are ~0.46 and ~0.78 for |MLAT| < 10°, respectively, and ~0.4 and ~0.74 for |MLAT| = 10°–25°, respectively; for the IMF <italic>B</italic><sub>z</sub>‐based model, the mean <italic>R</italic><sup>2</sup> and ROCC values are ~0.39 and ~0.74 for |MLAT| < 10°, respectively, and ~0.33 and ~0.70 for |MLAT| = 10°–25°, respectively. We provide all of the model information in the text and supporting information so that the developed chorus models can be used for the existing outer radiation belt electron models.</p> </abstract>