The evolution of intranetwork magnetic elements

We have studied the evolution of Intranetwork (IN) magnetic elements, using a particularly good series of very deep magnetograms obtained at Big Bear Solar Observatory. The magnetograms span an interval 10 hours long and cover an area of 310×240 arcsec². We are able to follow 528 intranetwork elements from birth to death. The analysis reveals the following results: (1). The appearance of IN elements can be classified into the following categories: half of the total IN elements emerge as clusters of mixed polarities somewhere within the network cells, one fifth appear as ephemeral regions (tiny bipoles), one fifth result from the merging of several elements of a given polarity, and one tenth appear by fragmentation of larger elements. (2). IN elements disappear in four ways: one third of total IN elements cancel with elements of opposite polarity, one third decay into weak fields without apparent interaction with other elements, one fourth merge with IN or network elements of the same polarity, and one tenth split into smaller IN elements below detecting limit. (3). About one ninth (one sixth) of the IN elements merge (cancel) with network features, consequently, part of the flux in network features is built up from former IN magnetic flux, and part is eliminated by IN elements. The net effect of merging and cancellation is a gradual reduction of the total flux of network elements in the 10 hours observational interval. It seems that not all the network magnetic flux is the remnant of active region magnetic flux.