On the calculation of electric diffusion coefficient of radiation belt electrons with in situ electric field measurements by THEMIS. Issue 3 (13th February 2016)

• Record Type: Journal Article
• Authors: Liu, Wenlong; Tu, Weichao; Li, Xinlin; Sarris, Theodore; Khotyaintsev, Yuri; Fu, Huishan; Zhang, Hui; Shi, Quanqi
• Is Part Of: Geophysical research letters. Volume 43:Issue 3(2016)
• Page Start: 1023
• Page End: 1030
• Publication Date: 2016-02-13
• Subjects: radiation belt -- radial diffusion -- ULF wave; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL067398
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Based on 7 years' observations from Time History of Events and Macroscale Interactions during Substorms (THEMIS), we investigate the statistical distribution of electric field Pc5 ULF wave power under different geomagnetic activities and calculate the radial diffusion coefficient due to electric field, D L L E, for outer radiation belt electrons. A simple empirical expression of D L L E THEMIS is also derived. Subsequently, we compare D L L E THEMIS to previous D LL models and find similar Kp dependence with the D L L E CRRES model, which is also based on in situ electric field measurements. The absolute value of D L L E THEMIS is constantly higher than D L L E CRRES, probably due to the limited orbital coverage of CRRES. The differences between D L L E THEMIS and the commonly used D L L M B ‐ A and D L L E Ozeke models are significant, especially in Kp dependence and energy dependence. Possible reasons for these differences and their implications are discussed. The diffusion coefficient provided in this paper, which also has energy dependence, will be an important contributor to quantify the radial diffusion process of radiation belt electrons. Key Points: Distributions of ULF PSD under different geomagnetic activities are studied Electric radial diffusion coefficients of radiation belt electrons are calculated Differences between our results and previous D LL models are discussed