The Day-to -day Ionospheric F2 -region variability and Sudden Stratospheric Warmings
Abstract
The low latitude ionospheric F2 --region is known to show a large day to day and hour to hour variability. Some of this variability has been related to sudden stratospheric warming. We therefore investigate the extent of ionospheric response to a number of stratospheric warming events using ionosonde data from six different stations in the Asian zone, covering a broad latitudinal region. In nearly all cases, we find ionospheric F2-region does respond to stratospheric warming within a week or two from the day of the event with an increase in foF2 around 10 hr L.T. and a decrease around 16 hr LT at the low latitude stations. These results are in conformity with those observed with GPS TEC data and attributed to the semidiurnal changes in the vertical ion drifts by Chau et al., 2009 and Goncharenko et al., 2010. However the variability in foF2 contributed by these warmings forms a minor component of the variability seen in the ionospheric data even during times when solar and magnetic activity is nearly absent. Further, it seems to us that it is difficult to quantify the changes in foF2 as well as in response times involved in these events. While the physical mechanisms for the ionospheric variability are known, the observed variability cannot be predicted with precision.
- Publication:
-
39th COSPAR Scientific Assembly
- Pub Date:
- July 2012
- Bibcode:
- 2012cosp...39.2033U