Quasi-Periodic Releases of Streamer Blobs and Velocity Variability of the Slow Solar Wind near the Sun

TL;DR

This study identifies quasi-periodic streamer blob releases during 2007 and shows that the slow solar wind velocity near the Sun varies significantly within hours, indicating high variability in the solar wind's behavior.

Contribution

It provides observational evidence of quasi-periodic streamer blob releases and demonstrates significant short-term velocity variability of the slow solar wind near the Sun.

Findings

10 quasi-periodic blob release events observed over three to four days

Blob velocities suggest large variability in slow solar wind speed within hours

Results align with previous studies near solar minimum

Abstract

We search for persistent and quasi-periodic release events of streamer blobs during 2007 with the Large Angle Spectrometric Coronagraph on the \textit{Solar and Heliospheric Observatory} and assess the velocity of the slow solar wind along the plasma sheet above the corresponding streamer by measuring the dynamic parameters of blobs. We find 10 quasi-periodic release events of streamer blobs lasting for three to four days. In each day of these events, we observe three-five blobs. The results are in line with previous studies using data observed near the last solar minimum. Using the measured blob velocity as a proxy for that of the mean flow, we suggest that the velocity of the background slow solar wind near the Sun can vary significantly within a few hours. This provides an observational manifestation of the large velocity variability of the slow solar wind near the Sun.