Statistics – Computation
Scientific paper
Jun 1974
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1974p%26ss...22..925b&link_type=abstract
Planetary and Space Science, Volume 22, Issue 6, p. 925-937.
Statistics
Computation
2
Scientific paper
An expression for the vertical velocity of the neutral atmosphere in the F-region is derived for Joule heating by the electric field that drives the auroral electrojet. When only vertical expansion is allowed, it is found that the vertical wind must always increase monotonically with altitude. The heating rate is proportional to the F-region ion density, so that appreciable heating, even during high electric fields, requires some production mechanism of ionization such as auroral secondary ionization or solar photoionization, in the lower F-region. Once started at night, when an ionizing source is present in the lower F-region, the expansion of the atmosphere transports ionization upward, thereby increasing the heating rate, and hence the expansion rate, i.e. positive feedback. Electric field strengths and F-region ion densities of 50 mV/m and 2 × 1011 e/m3, respectively, will produce vertal neutral wind speeds of several tens of m/sec in the 300-500 km altitude range. During periods of high magnetic activity, i.e. high electric field, Joule heating can produce large increases in the relative N2 concentration in the upper F-region; computations made with a simple model suggest that tenfold increases can occur at 400 km altitude 1/2-1 hr after the onset of magnetic activity, a result in agreement with satellite observations. When the Joule heating theory is applied to incoherent scatter data taken during one period of high heating, the horizontal electric field in the F-region is found to decrease markedly, possibly approaching zero as the field penetrates a weak, discrete auroral arc; the decrease began 10-20 km from the arc.
No associations
LandOfFree
Atmospheric expansion from Joule heating does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Atmospheric expansion from Joule heating, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Atmospheric expansion from Joule heating will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-986538