Abstract:
We present here latitudinal dependence of the diurnal
variation of the sporadic meteor flux rate based on
radar observations made from Thumba (8.5°N, 77°E),
Darwin (12.5°S, 130.8°E), Buckland Park (34.4°S,
138.3°E) and Davis (68.6°S, 78.0°E). The most striking
observation was the occurrence of a secondary peak at
Thumba at 03:00 local time (LT) prior to the occur-
rence of the commonly observed morning peak at
06:00 LT at all altitudes. Surprisingly, the secondary
peak was not observed at Darwin, which is a low-
latitude station close to Thumba, but in the southern
hemisphere. Further, we found that this secondary
peak has a clear seasonal variation. In summer (win-
ter), the primary (secondary) peak is larger than the
secondary (primary) peak and they are comparable in
the equinoxes. The observed diurnal rates also showed
seasonal and latitudinal variabilities, which can be
interpreted in terms of observing geometry of the spo-
radic meteor sources in the local sky. Our observations
also suggest that there exists asymmetry in northern
and southern hemisphere sporadic meteor flux.
