A Survey of EMIC Waves in Van Allen Probe Data.

Autor: Inglis, Andrew R.1,2 (AUTHOR) andrew.inglis@nasa.gov, Murphy, Kyle R.3,4,5 (AUTHOR), Halford, Alexa1 (AUTHOR)
Předmět:
Zdroj: Journal of Geophysical Research. Space Physics. Aug2024, Vol. 129 Issue 8, p1-12. 12p.
Abstrakt: Using an automated novel approach we conduct a reproducible systematic survey of electromagnetic ion cyclotron wave activity detected by Van Allen Probe B during the time period 2013 January 1–2019 July 15. We identify approximately 500 hr of EMIC wave activity, an occurrence rate of ∼ 0.85%. Accounting for satellite dwell time, we find that EMIC waves preferentially occur on the dayside, between 9 and 15 magnetic local time. This is true for both the H+ and He+wavebands. Higher amplitude waves are found at higher values of L shell, while weaker waves occur at low L. The highest amplitudes are concentrated at high L near dawn and dusk. It is also found that EMIC wave occurrence is enhanced during periods of strong geomagnetic activity, with an occurrence rate of 2.7%. During storm times, waves preferentially occur in the afternoon and early evening sectors. The full list of electromagnetic ion cyclotron wave detection times and their properties is made publicly available to the community. This provides a reference catalog for comparison with other magnetospheric phenomena and other wave databases. Plain Language Summary: Electromagnetic Ion Cyclotron (EMIC) waves are found throughout Earth's magnetosphere and the solar system. These waves in Earth's magnetosphere interact with the ring current and radiation belt population and push these particles into our atmosphere. Thus, it is useful to know when and where these waves occur. In this paper, we present a new approach toward identifying these waves in large data sets. Using this new approach, we identified 500 hr of EMIC waves from the Van Allen Probe B data set between Jan 2013–July 2019. Our catalog of events follows similar statistics found for EMIC waves by others, validating our methodology. Like others, we found that the waves occur more frequently on the dayside of the Earth. Higher amplitude waves were found at greater distances from the Earth, close to the edge of the magnetosphere. It was also found that the wave activity was greater during periods of geomagnetic activity than during quiet conditions. And in the interest of open science, we have made both the detection code and the list of waves available to the public. Key Points: We conduct a survey of electromagnetic ion cyclotron waves detected by Van Allen Probe B between 2013 January 1–2019 July 15The overall EMIC wave occurrence rate was ∼0.85% with a dayside preference. Stronger waves are found at higher L shells and during stormsThe full list of EMIC wave detection times and their properties is made publicly available to the community, along with the methodology [ABSTRACT FROM AUTHOR]
Databáze: GreenFILE