Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere
Empirical models have been previously developed using the large dataset of satellite observations to obtain the global distributions of total electron density and whistler-mode wave power, which are important in modeling radiation belt dynamics. In this paper, we apply the empirical models to constr...
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Frontiers Media S.A.
2023-09-01
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| Series: | Frontiers in Astronomy and Space Sciences |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fspas.2023.1232702/full |
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| author | Qianli Ma Qianli Ma Xiangning Chu Donglai Ma Sheng Huang Wen Li Jacob Bortnik Xiao-Chen Shen |
| author_facet | Qianli Ma Qianli Ma Xiangning Chu Donglai Ma Sheng Huang Wen Li Jacob Bortnik Xiao-Chen Shen |
| author_sort | Qianli Ma |
| collection | DOAJ |
| description | Empirical models have been previously developed using the large dataset of satellite observations to obtain the global distributions of total electron density and whistler-mode wave power, which are important in modeling radiation belt dynamics. In this paper, we apply the empirical models to construct the total electron density and the wave amplitudes of chorus and hiss, and compare them with the observations along Van Allen Probes orbits to evaluate the model performance. The empirical models are constructed using the Hp30 and SME (or SML) indices. The total electron density model provides an overall high correlation coefficient with observations, while large deviations are found in the dynamic regions near the plasmapause or in the plumes. The chorus wave model generally agrees with observations when the plasma trough region is correctly modeled and for modest wave amplitudes of 10–100 pT. The model overestimates the wave amplitude when the chorus is not observed or weak, and underestimates the wave amplitude when a large-amplitude chorus is observed. Similarly, the hiss wave model has good performance inside the plasmasphere when modest wave amplitudes are observed. However, when the modeled plasmapause location does not agree with the observation, the model misidentifies the chorus and hiss waves compared to observations, and large modeling errors occur. In addition, strong (>200 pT) hiss waves are observed in the plumes, which are difficult to capture using the empirical model due to their transient nature and relatively poor sampling statistics. We also evaluate four metrics for different empirical models parameterized by different indices. Among the tested models, the empirical model considering a plasmapause and controlled by Hp* (the maximum Hp30 during the previous 24 h) and SME* (the maximum SME during the previous 3 h) or Hp* and SML has the best performance with low errors and high correlation coefficients. Our study indicates that the empirical models are applicable for predicting density and whistler-mode waves with modest power, but large errors could occur, especially near the highly-dynamic plasmapause or in the plumes. |
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| issn | 2296-987X |
| language | English |
| last_indexed | 2024-03-12T01:37:34Z |
| publishDate | 2023-09-01 |
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| spelling | doaj.art-cc0ea5eeafb9464a90526620ac1e77bc2023-09-11T05:02:16ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2023-09-011010.3389/fspas.2023.12327021232702Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphereQianli Ma0Qianli Ma1Xiangning Chu2Donglai Ma3Sheng Huang4Wen Li5Jacob Bortnik6Xiao-Chen Shen7Center for Space Physics, Boston University, Boston, MA, United StatesDepartment of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, United StatesLaboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, United StatesDepartment of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, United StatesCenter for Space Physics, Boston University, Boston, MA, United StatesCenter for Space Physics, Boston University, Boston, MA, United StatesDepartment of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, United StatesCenter for Space Physics, Boston University, Boston, MA, United StatesEmpirical models have been previously developed using the large dataset of satellite observations to obtain the global distributions of total electron density and whistler-mode wave power, which are important in modeling radiation belt dynamics. In this paper, we apply the empirical models to construct the total electron density and the wave amplitudes of chorus and hiss, and compare them with the observations along Van Allen Probes orbits to evaluate the model performance. The empirical models are constructed using the Hp30 and SME (or SML) indices. The total electron density model provides an overall high correlation coefficient with observations, while large deviations are found in the dynamic regions near the plasmapause or in the plumes. The chorus wave model generally agrees with observations when the plasma trough region is correctly modeled and for modest wave amplitudes of 10–100 pT. The model overestimates the wave amplitude when the chorus is not observed or weak, and underestimates the wave amplitude when a large-amplitude chorus is observed. Similarly, the hiss wave model has good performance inside the plasmasphere when modest wave amplitudes are observed. However, when the modeled plasmapause location does not agree with the observation, the model misidentifies the chorus and hiss waves compared to observations, and large modeling errors occur. In addition, strong (>200 pT) hiss waves are observed in the plumes, which are difficult to capture using the empirical model due to their transient nature and relatively poor sampling statistics. We also evaluate four metrics for different empirical models parameterized by different indices. Among the tested models, the empirical model considering a plasmapause and controlled by Hp* (the maximum Hp30 during the previous 24 h) and SME* (the maximum SME during the previous 3 h) or Hp* and SML has the best performance with low errors and high correlation coefficients. Our study indicates that the empirical models are applicable for predicting density and whistler-mode waves with modest power, but large errors could occur, especially near the highly-dynamic plasmapause or in the plumes.https://www.frontiersin.org/articles/10.3389/fspas.2023.1232702/fullempirical modeltotal electron densitychorus wave amplitudehiss wave amplitudeerror metricradiation belt |
| spellingShingle | Qianli Ma Qianli Ma Xiangning Chu Donglai Ma Sheng Huang Wen Li Jacob Bortnik Xiao-Chen Shen Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere Frontiers in Astronomy and Space Sciences empirical model total electron density chorus wave amplitude hiss wave amplitude error metric radiation belt |
| title | Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere |
| title_full | Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere |
| title_fullStr | Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere |
| title_full_unstemmed | Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere |
| title_short | Evaluating the performance of empirical models of total electron density and whistler-mode wave amplitude in the Earth’s inner magnetosphere |
| title_sort | evaluating the performance of empirical models of total electron density and whistler mode wave amplitude in the earth s inner magnetosphere |
| topic | empirical model total electron density chorus wave amplitude hiss wave amplitude error metric radiation belt |
| url | https://www.frontiersin.org/articles/10.3389/fspas.2023.1232702/full |
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