A Tale of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere

[摘要] Weusehigh-resolutionobservationsoftheSuninCaIIH(3968 Å)fromtheSolarOpticalTelescopeonHinodetoshowthatthereareatleasttwotypesofspiculesthatdominatethestructureofthemagneticsolarchromosphere.Bothtypesaretiedtotherelentlessmagnetoconvectivedrivinginthephotosphere,buthaveverydifferentdynamicproperties.“Type-I”spiculesaredrivenbyshockwavesthatformwhenglobaloscillationsandconvectiveflowsleakintotheupperatmospherealongmagneticfieldlineson3–7 minutetimescales.“Type-II”spiculesaremuchmoredynamic:theyformrapidly(in$$sim$$10s),areverythin($$le200$$kmwide),havelifetimesof10–150s(atanyoneheight),andseemtoberapidlyheatedto(atleast)transitionregiontemperatures,sendingmaterialthroughthechromosphereatspeedsoforder50–150 km s$$^{-1}$$.ThepropertiesofTypeIIspiculessuggestaformationprocessthatisaconsequenceofmagneticreconnection,typicallyinthevicinityofmagneticfluxconcentrationsinplageandnetwork.BothtypesofspiculesareobservedtocarryAlfvénwaveswithsignificantamplitudesoforder20 km s$$^{-1}$$.

[学科分类] 天文学(综合)

[关键词] "Sun: chromosphere";"Sun: transition region"