Sequential chromospheric brightenings: The case for chromospheric evaporation

Abstract

Sequential chromospheric brightenings (SCBs [Balasubramaniam, K.S., Pevtsov, A.A., Neidig, D.F., Cliver, E.W., Thompson, B.J., Young, C.A., Martin, S.F., & Kiplinger, A., 630, 1160, 2005.]) are observed in conjunction with some strong solar flares, prominence eruptions, and coronal mass ejections (CMEs). SCBs are seen as wave-like trains of increased brightening of chromospheric network elements propagating away from the site of eruption (flare/CME). Although network magnetic field usually has mixed polarity, only areas of one (prevailing) polarity are seen as SCBs; there are no brightenings in neighboring network elements of opposite (minor) polarity. This polarity rule, relative timing of SCBs in respect to beginning of flare/CME, and their location in respect to overall topology of each event suggest that SCBs may be caused by high energy particles precipitating from the reconnection site at the tail of CME. In this work we use TRACE, SOHO/MDI, and H-alpha OSPAN data to demonstrate that indeed SCB locations exhibit several properties of chromospheric evaporation.