Utilizing the data of microbarometric waves on ground level, radiosonde reports and solar radiations obtained from various observation stations in China during the annular solar eclipse on September 23, 1987, the mech...Utilizing the data of microbarometric waves on ground level, radiosonde reports and solar radiations obtained from various observation stations in China during the annular solar eclipse on September 23, 1987, the mechanism ,of AGWs excited by the eclipse, the spectral characteristics and the local differences have been studied, and the results have been compared with those from the ionospheric sounding at the same time. It turns out that there were AGWs excited certainly during this annular solar eclipse, their periods are obviously in accordance with the duration of the fluctuation in the direct solar radiation.展开更多
Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06：28 UT on 12 May, 2008. One is detected 7.9 rain after the earthquake an...Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06：28 UT on 12 May, 2008. One is detected 7.9 rain after the earthquake and had an intensive ＂N＂ shape oscillated waveform with a pronounced amplitude of about 1 TECU, which propagates approximately southward to the distance about 1000 km with the horizontal phase velocity of 600±84 m/s and the period of 9.5±1.3 min. The other is detected 8.5 min after the earthquake and has an oscillated waveform more like a positive pulse with an amplitude of about 0.5 TECU, which propagates eastward to the distance about 800 km with the horizontal phase velocity of 720＋59 m/s and the period of 7.4±0.8 min. These two coseismic ionospheric disturbances are caused by the acoustic gravity waves excited by partial trans-formation of the acoustic waves originated from the energy release of the earthquake, somewhere near the epicenter. The directional preferences of these two coseismic ionospheric disturbances may be associated with the oblique geomagnetic field lines and the background winds filtering effect.展开更多
文摘Utilizing the data of microbarometric waves on ground level, radiosonde reports and solar radiations obtained from various observation stations in China during the annular solar eclipse on September 23, 1987, the mechanism ,of AGWs excited by the eclipse, the spectral characteristics and the local differences have been studied, and the results have been compared with those from the ionospheric sounding at the same time. It turns out that there were AGWs excited certainly during this annular solar eclipse, their periods are obviously in accordance with the duration of the fluctuation in the direct solar radiation.
基金supported by the Chinese Academy of Sciences(Grant No.KZZDEW-01-2)the National Natural Science Foundation of China(Grant Nos.41274162,41131066,41304126)the National Basic Research Program of China(Grant No.2011CB811405)
文摘Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06：28 UT on 12 May, 2008. One is detected 7.9 rain after the earthquake and had an intensive ＂N＂ shape oscillated waveform with a pronounced amplitude of about 1 TECU, which propagates approximately southward to the distance about 1000 km with the horizontal phase velocity of 600±84 m/s and the period of 9.5±1.3 min. The other is detected 8.5 min after the earthquake and has an oscillated waveform more like a positive pulse with an amplitude of about 0.5 TECU, which propagates eastward to the distance about 800 km with the horizontal phase velocity of 720＋59 m/s and the period of 7.4±0.8 min. These two coseismic ionospheric disturbances are caused by the acoustic gravity waves excited by partial trans-formation of the acoustic waves originated from the energy release of the earthquake, somewhere near the epicenter. The directional preferences of these two coseismic ionospheric disturbances may be associated with the oblique geomagnetic field lines and the background winds filtering effect.
