Variability of the ionosphere

Details Variability of the ionosphere Variability of the ionosphere

May 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000jastp..62..685f&link_type=abstract

Journal of Atmospheric and Solar-Terrestrial Physics, Volume 62, Issue 8, p. 685-693.

Physics

95

Scientific paper

Hourly foF2 data from over 100 ionosonde stations during 1967-89 are examined to quantify F-region ionospheric variability, and to assess to what degree the observed variability may be attributed to various sources, i.e., solar ionizing flux, meteorological influences, and changing solar wind conditions. Our findings are as follows. Under quiet geomagnetic conditions (Kp<1), the /1-σ (/σ is the standard deviation) variability of Nmax about the mean is approx. +/-25-35% at `high frequencies' (periods of a few hours to 1-2 days) and approx. +/-15-20% at `low frequencies' (periods approx. 2-30 days), at all latitudes. These values provide a reasonable average estimate of ionospheric variability mainly due to ``meteorological influences'' at these frequencies. Changes in Nmax due to variations in solar photon flux, are, on the average, small in comparison at these frequencies. Under quiet conditions for high-frequency oscillations, Nmax is most variable at anomaly peak latitudes. This may reflect the sensitivity of anomaly peak densities to day-to-day variations in F-region winds and electric fields driven by the E-region wind dynamo. Ionospheric variability increases with magnetic activity at all latitudes and for both low and high frequency ranges, and the slopes of all curves increase with latitude. Thus, the responsiveness of the ionosphere to increased magnetic activity increases as one progresses from lower to higher latitudes. For the 25% most disturbed conditions (Kp>4), the average /1-σ variability of Nmax about the mean ranges from approx. +/-35% (equator) to approx. +/-45% (anomaly peak) to approx. +/-55% (high-latitudes) for high frequencies, and from approx. +/-25% (equator) to approx. +/-45% (high-latitudes) at low frequencies. Some estimates are also provided on Nmax variability connected with annual, semiannual and 11-year solar cycle variations.

Affiliated with

Also associated with

No associations

Rating

Variability of the ionosphere 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 Variability of the ionosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variability of the ionosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1195203