Anomalous velocity fields in McMath 16064

McMath 16064 was first seen on the east limb on May 29, 1979, associated with a single spot having a developed penumbra in the preceding part. In the following part, only an extended spotless plage was seen. This report presents the comparative study of magnetic fields and photospheric velocity in McMath 16064. The purpose is to find empirical evidence for the role of the configuration of magnetic and velocity fields in relation to flare occurrence. On the basis of chromospheric structure, longitudinal magnetic fields, line-of-sight velocity pattern, and structural peculiarities of sunspots during their growth in an active region with low flare productivity, the condition capable of producing flare was investigated. An aspect of the present analysis is the existence of anomalous velocity field in relation to emerging flux region. The observation indicates that the emergence of horizontal field could be associated with the upward motion of the photospheric layer. In view of the location of flare, the combination of both sheared field and emerging flux may be speculated as the condition required for flare incidence. (J.P.N.)