  Sunspot penumbrae show a fine structure in continuum intensity that displays
considerable dynamics. The magnetic field, in contrast, although also highly
structured, has appeared to be relatively static. Here we report the discovery
of inward moving magnetic enhancements in the penumbrae of two regular sunspots
based on time series of SOHO/MDI magnetograms. Local enhancements of the LOS
component of the magnetic field in the inner part of the penumbral region move
inward to the umbra-penumbra boundary with a radial speed of about 0.3 km
s$^{-1}$. These local inward-moving enhancements of the LOS component of the
magnetic fields appear to be relatively common. They are associated with dark
structures and tend to display downflows relatively to the penumbral
background. Possible explanations are discussed.
