THE DATA:
The Australian ionosonde network extends from Casey (in the polar cap) to Vanimo (2 degrees south of the geographic equator). As well as offering a good latitudinal chain of observing sites, there is useful longitudinal coverage at mid latitudes with Mundaring (116E) to Norfolk Island (170E). Although digital ionograms are now collected at all 12 Australian ionosonde stations, only film records (other than Casey) are available for the November 1993 study period. In addition to the sites where data are recorded, additional data are now being sought from New Zealand where the Christchurch and Auckland ionosondes were operating. This extends the mid latitude longitudinal coverage. At present (4 Aug) all foF2 and M(3000)F2 data are have been rescaled at 15 minute resolution and are now being entered.
PRELIMINARY OBSERVATIONS:
Based on hourly scaled data, a positive phase ionospheric storm started close to 00UT, November 4. It appeared first as a positive phase effect that was possibly seen at Macquarie Island (54.5S, 159E) before 00UT. The positive phase storm progressed northwards and was possibly present at Darwin (12.5S) and is clearly present at Townsville (19.6S). On the 5th November there is a well developed negative phase storm affecting Hobart, Canberra and Mundaring. Townsville is marginally depressed, compared with Nov 1-3. Darwin is depressed on the 6 Nov. Data are lost at Mawson and Macquarie Island from Nov 4 due to strong absorption caused by precipitating particles. This continues, gradually abating by 8 Nov at Macquarie and 11 Nov at Mawson during which time there are occasional ionospheric storm effects seen at mid latitudes at isolated locations. During the Nov 1-14 period, the storm did not appear to have an obvious effect on spread F observed at all stations, with the possible exception of Hobart.
SOME THINGS I AM INTERESTED IN HEARING FROM OTHERS:
These data, when reprocessed, can be compared with models. So far, Dave Anderson, Barbara Emery, Tim Fuller-Rowell and Phil Richards have offered model outputs. I will be interested in any other models.
The start of the positive phase storm is hard to determine accurately. Any suggestions about when this effect is likely to have been initiated will be of obvious interest.
Any abrupt changes in magnetospheric configurations may possibly be seen in short term ionospheric changes.
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