Keywords:Ionospheric Scintillation, Middle Latitude, Longitude Difference, Gravity Wave
Ionospheric scintillation shows great regional characteristics. In this paper, we studied the GPS amplitude scintillations (S4 larger than 0.2) from 2010 to 2013 at station Darwin (12.45°S, 130.95°E), Weipa (12.63°S, 141.88°E) and Willis Island (16.29°S, 149.97°E) in Australia, to show the variations of the scintillation characteristics among these three stations with similar latitude but different longitudes.The results show that: The occurrences of scintillation during sunset hours (Osunset, LT 18:00-24:00) are similar to those beyond the sunset hours (Oother, LT 0:00-18:00) at all stations, but they have different seasonal variations: at Darwin the Osunset is high in around June and December, but the Oother is high in around April and September, so they have great difference; at Weipa the Osunset is high in around April and October, and the Oother is high in around April and September, always has one month difference with the Osunset; at Willis Island the Osunset is high in around January and November in 2012 but high in April and December in 2013, and the Oother has similar variation trend with Osunset. Scintillations are stronger from 2010 to 2012 than in 2013 at Darwin and Weipa, but reverse at Willis Island. Comparing the different stations, only the seasonal variation trends of Oother at Darwin and at Weipa are similar. We also compare our statistics with gravity wave measurement by GOCE satellite (Gravity Field and Stead-state Ocean Circulation Explore). The scintillation Osunset don’t show obvious association with gravity wave activities, while the Oother seem to have reverse trends to those of gravity wave activities at the three stations.