M. Brittnacher et al., A DAYSIDE AURORAL ENERGY DEPOSITION CASE-STUDY USING THE POLAR ULTRAVIOLET IMAGER, Geophysical research letters, 24(8), 1997, pp. 991-994
In this letter, we report preliminary results from a study of dayside
auroral energy deposition during quiet times using global auroral imag
es acquired by the Ultraviolet Imager experiment on the Polar spacecra
ft. Solar wind plasma and interplanetary magnetic field measurements f
rom the Wind spacecraft and Kp values were used to characterize the st
ate of the magnetosphere. The auroral oval was observed for a two-hour
period in spring and summer during relatively quiet times (K-P simila
r or equal to 0 to 1). We find that, although the nightside energy dep
osition rate varied by an order of magnitude to as low as 1 x 10(16) e
rg s(-1) (1 gigawatt), the dayside was much less variable and remained
between 4 and 10 x 10(16) erg s(-1).