Ionospheric disturbances in the vicinity of the Chelyabinsk meteoroid explosive disruption as inferred from dense GPS observations

The paper describes results of studying effects of total electron content (TEC) variations triggered by the Chelyabinsk meteoroid airburst as inferred from unique data of a dense GPS network located around the final part of the meteoroid atmospheric path. Well-pronounced TEC disturbances with an average period of about 10 min and amplitude of 0.07-0.5 TECU (total electron content unit, 1 TECU = 10(16) elm(-2)) were detected. These disturbances were initiated by an ionospheric source activated about 5-6min after the airburst. The disturbance velocity damping with time and distance from the airburst was revealed using a GPS interferometric technique. Several modes of TEC disturbances with propagation velocities ranging from 250 to 660 m/s were distinguished through the distance-time diagram analysis. The estimated position of ionospheric source of TEC disturbances is shifted 36 km southwestward from the airburst, which is most likely to be associated with the conjoint influence of TEC data errors, damping and anisotropy of TID propagation velocity.