Simultaneous disappearances of plasmaspheric hiss, exohiss, and chorus waves triggered by a sudden decrease in solar wind dynamic pressure

• Published in: Geophysical research letters Vol. 44; no. 1; pp. 52 - 61
• Main Authors: Liu, Nigang, Su, Zhenpeng, Gao, Zhonglei, Zheng, Huinan, Wang, Yuming, Wang, Shui, Spence, H. E., Reeves, G. D., Baker, D. N., Blake, J. B., Funsten, H. O., Wygant, J. R.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 16.01.2017; John Wiley & Sons, Inc
• Subjects: chorus; Chorus waves; Dynamic pressure; Dynamics; exohiss; Free energy; Geomagnetic field; Geomagnetic fields; Geomagnetism; Hiss; Inhomogeneity; Leakage; Magnetic fields; Magnetism; Magnetospheres; Nonlinear dynamics; plasmaspheric hiss; Pressure; Quenching; Radiation; Saturn; Solar wind; wave disappearance; wave generation; Whistlers
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2016GL071987

Magnetospheric whistler mode waves are of great importance in the radiation belt electron dynamics. Here on the basis of the analysis of a rare event with the simultaneous disappearances of whistler mode plasmaspheric hiss, exohiss, and chorus triggered by a sudden decrease in the solar wind dynamic pressure, we provide evidences for the following physical scenarios: (1) nonlinear generation of chorus controlled by the geomagnetic field inhomogeneity, (2) origination of plasmaspheric hiss from chorus, and (3) leakage of plasmaspheric hiss into exohiss. Following the reduction of the solar wind dynamic pressure, the dayside geomagnetic field configuration with the enhanced inhomogeneity became unfavorable for the generation of chorus, and the quenching of chorus directly caused the disappearances of plasmaspheric hiss and then exohiss. Key Points First report of simultaneous disappearances of plasmaspheric hiss, exohiss, and chorus triggered by a sudden decrease in solar wind pressure Disappearance of chorus caused by the increase of dayside magnetic field inhomogeneity rather than the change of local electron free energy Disappearances of plasmaspheric hiss and exohiss resulting from the chorus quenching rather than the change of local plasma condition