17:15 〜 18:45
[PEM12-P11] Comparison of satellite and ground-based observations of the sporadic E layer over Japan.
キーワード：スポラディックE層、衛星観測、地上観測
The Sporadic E(Es) Layer is a significant obstacle for radio communication and GNSS positioning. Its altitude and intensity are important information for space weather applications.
There are two methods of observing the sporadic E layer: satellite observations using the GNSS radio-occultation method and ground-based ionosonde observations. In this study, we compare the height and intensity of the sporadic E layer observed simultaneously by both methods over Japan to verify their consistency.
We use COSMIC-1 and 2 and ionosondes observed at 4 sites in Japan. The range of satellite observations was analyzed in two patterns: [±1.5 degrees latitude and ±3 degrees longitude] and [±2 degrees latitude and ±5 degrees longitude].
The analysis shows that the difference in the height of the sporadic E layer observed by both methods (satellite data minus ground observation data) varies with the latitude of the observation sites: 0 km in Okinawa, 2.5 km in Yamagawa and Kokubunji, and -3 km in Wakkanai. When separated by day and night, we found the difference is larger at night than at day. In addition, the differences become larger for Es with S4 index above 0.4. It is found that the intenstity of S4 index and the foEs in the simultanous observations have very low correlation coefficient of 0.2 for most observation points and LTs.
Several factors contribute to the differences, such as differences in measuring method, systematic errors and other uncertainties in each observation methods.
There are two methods of observing the sporadic E layer: satellite observations using the GNSS radio-occultation method and ground-based ionosonde observations. In this study, we compare the height and intensity of the sporadic E layer observed simultaneously by both methods over Japan to verify their consistency.
We use COSMIC-1 and 2 and ionosondes observed at 4 sites in Japan. The range of satellite observations was analyzed in two patterns: [±1.5 degrees latitude and ±3 degrees longitude] and [±2 degrees latitude and ±5 degrees longitude].
The analysis shows that the difference in the height of the sporadic E layer observed by both methods (satellite data minus ground observation data) varies with the latitude of the observation sites: 0 km in Okinawa, 2.5 km in Yamagawa and Kokubunji, and -3 km in Wakkanai. When separated by day and night, we found the difference is larger at night than at day. In addition, the differences become larger for Es with S4 index above 0.4. It is found that the intenstity of S4 index and the foEs in the simultanous observations have very low correlation coefficient of 0.2 for most observation points and LTs.
Several factors contribute to the differences, such as differences in measuring method, systematic errors and other uncertainties in each observation methods.