THE EVOLUTION OF MAGNETIC NETWORK ELEMENTS IN THE QUIET SUN

Using the 155-h coordinated magnetograph data of Huairou and Big Bear Solar Observatories, we have studied the evolution and lifetime of mag netic network elements in an enhanced network region. Both statistical and counting methods give a mean lifetime of network elements of 50 h . The network elements are divided into two categories according their evolution: ''breakup'' and ''merging''. They have similar average lif etimes. We also find that the number of the elements that disappear by merging is about twice that by breakup. This may indicate that the cr eation and disappearance of magnetic network elements are balanced.