Plasma Blobs Associated With Medium-Scale Traveling Ionospheric Disturbances

Plasma blobs represent plasma density enhancements with respect to ambient plasma. The formation of blobs in low and middle latitudes is understood in association with either equatorial plasma bubbles or medium-scale traveling ionospheric disturbances (MSTIDs). This study reports four blob events identified from the Swarm satellite observations in 2014. Those blobs show the conjugate property and the alignment in the northwest-southeast direction in the Northern Hemisphere and southwest-northeast direction in the Southern Hemisphere. These are the typical characteristics of nighttime MSTIDs. The observation of MSTIDs in the total electron content maps and the absence of bubbles in the equatorial region at the times of the blob detection further support the association of those blobs with MSTIDs.