1. Yue Chen (Los Alamos National Laboratory)
Temporal and Spatial Correlation between Chorus Waves and Substorm Electron Precipitation
Yue Chen (Los Alamos National Laboratory)
Using conjugate observations from RBPS and NOAA POES, we want to:
Reexamine the temporal and spatial correlation between chorus waves and precipitating ~10s keV electrons.
Quantify the performance of using electron precipitation as the chorus wave proxy.
Explore the connection between proton precipitation and EMIC waves.
[Chen et al., 2014 GRL]
Van Allen Probes SWG Meeting, APL, July 2015

2. 1. Temporal Correlation
Wave (RBSP) and e- (POES) data from same (L, MLT) bins but different altitude.
Clear one-to-one relation between intensified chorus waves and 30keV electron precipitation in the dawn sector .
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3. 2. Temporal Correlation (cont’d)
Clear one-to-one relation between (most) intensified chorus waves and 30keV electron precipitation in the noon sector .
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4. 3. Temporal Correlation (cont’d)
Clear one-to-one relation between (most) intensified chorus waves and 30keV electron precipitation except for the evening sector.
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5. 4. Spatial Correlation
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6. 5. Spatial Correlation (cont’d)
Spatial correlation is confirmed and quantified.
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7. 6. Performance Evaluation (the Oct. 2012 storm)
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8. 7. Performance Evaluation (cont’d)
PE for RBSP-A: 0.37; PE for RBSP-B: 0.11 (in comparison, PEs using empirical averaged distributions are ~ -1.2 for both.
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9. 8. One Case EMIC Wave Related to Proton Precipitation
Copied from Engerets, et al. [2014]
Quantify the correlation…
This case shows the relation between EMIC waves and ring current proton precipitation.
Indicate the possibility of using proton precipitation from LEO as EMIC proxy.
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10. Summary and Conclusions
We have confirmed the significant one-to-one correlation between intensified chorus waves and precipitation events of substorm events, using conjugate RBSP and NOAA POES observations.
We also statistically demonstrated the significant correlation between chorus waves and substorm electron precipitation during periods with high AE values (>300nT).
Based on the temporal and spatial correlation, it is reasonable to use precipitating electrons as the chorus wave proxy for event-specific chorus wave global distributions, which are more reliable than using statically averaged distributions.
We also present a case showing a similar connection may exist between the EMIC waves and precipitating protons.
Acknowledgements: We are grateful for the use of data from NOAA POES MEPT and Van Allen Probes EMFISIS measurements. Thanks are extended to all PIs and data teams.
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