Prediction of the AU, AL, and AE indices using solar wind parameters. Issue 12 (20th December 2013)

• Record Type: Journal Article
• Authors: Luo, Bingxian; Li, Xinlin; Temerin, M.; Liu, Siqing
• Is Part Of: Journal of geophysical research. Volume 118:Issue 12(2013:Dec.)
• Page Start: 7683
• Page End: 7694
• Publication Date: 2013-12-20
• Subjects: Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2013JA019188
• Languages: English
• ISSNs: 2169-9380

Abstract

<abstract abstract-type="main" id="jgra50718-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="jgra50718-para-0001">[1] An empirical model that predicts the <italic>AU</italic> index, a measure of the Earth's east electrojet, derived from magnetometers in the Northern Hemisphere, is introduced together with an improved <italic>AL</italic> model which, combined with the <italic>AU</italic> model, produces an <italic>AE</italic> model. All models are based on solar wind and interplanetary magnetic field parameters and the solar <italic>F</italic><sub>10.7</sub> index for the years 1995 to 2001. The linear correlation coefficient (LC) between the 10 min averaged <italic>AU</italic> index and the model is 0.846 for the years 1995–2001. The LC for the updated <italic>AL</italic> model is 0.846, and using <italic>AE</italic>=<italic>AU</italic>−<italic>AL</italic>, the LC for the <italic>AE</italic> model is 0.888. The better LC of the <italic>AE</italic> model over <italic>AU</italic> and <italic>AL</italic> models is because <italic>AU</italic> and <italic>AL</italic> are better correlated than their errors. The models show that (1) solar ultraviolet intensity plays a significant role in auroral activity by changing the ionospheric conductivity and scale height. Increasing solar ultraviolet intensity increases the eastward electrojet as measured by <italic>AU</italic> but decreases the westward electrojet as measured by <italic>AL</italic>; (2) solar wind dynamic pressure also affects the auroral electrojet indices, although they are much more strongly dependent on the solar wind velocity and the interplanetary magnetic field; (3) <italic>AU</italic> and <italic>AL</italic> behave differently during geomagnetic storm main phases: <italic>AU</italic>, unlike <italic>AL</italic>, can drop to a small value during storms; (4) the longer averaged auroral electrojets indices can be predicted well but shorter timescale variations are less predictable.</p> </abstract>