Solar eclipse effects in the ionosphere observed by continuous Doppler sounding

The ionospheric response to the solar eclipses of 20 March 2015 above the Czech Republic, 9 March 2016 above Taiwan, and 26 February 2017 above South Africa was studied. A distinct bipolar pulse was observed in ionospheric Doppler shift measurements above the Czech Republic (Central Europe) and above Taiwan (Eastern Asia). It is a local phenomenon clearly related with changes of electron density in the ionosphere induced by the passage of the Moon shadow above the measurement sites. The solar eclipse in Taiwan was rather small, with a maximum obscuration of 0.22. Yet, it obviously influenced the ionosphere on time scales above 100 min. The solar eclipse in South Africa occurred shortly before sunset and it is likely that ionospheric effects were masked by gravity waves generated by the evening solar terminator.