Observations of Chromospheric Anemone Jets with Hinode SOT and Hida Ca II Spectroheliogram

TL;DR

This study presents simultaneous multi-instrument observations of chromospheric anemone jets, revealing their generation in the lower chromosphere, their dynamic properties, magnetic associations, and energy release mechanisms, contributing to understanding solar active region phenomena.

Contribution

First simultaneous observations of chromospheric anemone jets with Hinode SOT and Hida Ca II spectroheliogram, providing detailed insights into their magnetic and energetic properties.

Findings

Jets are generated in the lower chromosphere.

Jet lengths are 0.4-5 Mm with lifetimes of 40-320 sec.

Magnetic reconnection rates are around 10^{16} Mx/s, releasing energies of 10^{26} erg.

Abstract

We present the first simultaneous observations of chromospheric "anemone" jets in solar active regions with Hinode SOT Ca II H broadband filetergram and Ca II K spetroheliogram on the Domeless Solar Telescope (DST) at Hida Observatory. During the coordinated observation, 9 chromospheric anemone jets were simultaneously observed with the two instruments. These observations revealed three important features, i.e.: (1) the jets are generated in the lower chromosphere, (2) the length and lifetime of the jets are 0.4-5 Mm and 40-320 sec, (3) the apparent velocity of the jets with Hinode SOT are 3-24 km/s, while Ca II K3 component at the jets show blueshifts (in 5 events) in the range of 2- 6 km/s. The chromospheric anemone jets are associated with mixed polarity regions which are either small emerging flux regions or moving magnetic features. It is found that the Ca II K line often show red or blue asymmetry in K2/K1 component: the footpoint of the jets associated with emerging flux regions often show redshift (2-16 km/s), while the one with moving magnetic features show blueshift (around 5 km/s). Detailed analysis of magnetic evolution of the jet foaming regions revealed that the reconnection rate (or canceling rate) of the total magnetic flux at the footpoint of the jets are of order of 10^{16} Mx/s, and the resulting magnetic energy release rate (1.1-10) x 10^{24} erg/s, with the total energy release (1-13) x 10^{26} erg for the duration of the magnetic cancellations, 130s. These are comparable to the estimated total energy, 10^{26} erg, in a single chromospheric anemone jet. An observation-based physical model of the jet is presented. The relation between chromospheric anemone jets and Ellerman bombs is discussed.