Analyzing Ionosphere TEC and ROTI Responses on 2010 August High Speed Solar Winds

Abstract

The high-speed solar winds stream (HSSWS) generated by coronal hole can produce large interplanetary magnetic field magnitude oscillations, leading to high latitude geomagnetic disturbances, and ionospheric responses as well. This paper has analyzed the global ionospheric total electron content (TEC) and rate of TEC index (ROTI) responses during the high speed solar winds stream occurred from 23 to 29 August, 2010. Ground Global Navigation Satellite System (GNSS) network was mainly used to investigate ionosphere TEC and ROTI behaviors. It has revealed that high latitudes and middle latitudes ionosphere suffered most during this event, with hemisphere asymmetry characteristics. Both TEC variations and ionosphere irregularities were analyzed. The HSSWS event brings to strong ionosphere irregularities represented by large ROTI enhancements at high latitudes. The concentrated ionosphere irregularities were closely related to the intensity of Auroral Electrojet enhancement activities. The ROTI enhancements at high latitudes, including polar cap, aurora, and sub-aurora are also influenced by solar zenith angle; all the prominent ROTI increments are observed in the ranges between 70° and 110° solar zenith angles; while the ROTI enhancements at low latitudes and equator are mostly found in the ranges between 130° and 170° solar zenith angles. The ionosphere disturbance triggered by the HSSWS is also noticed by some remarkable changes of F2 layer peak height. The work is contributing to the understanding of the theoretical coupling mechanism between high speed solar winds stream and magneto-ionosphere responses and provides a reference for space weather analysis and forecasting under similar events.