Evolution of advection fog observed by Ka-band radars

This paper discusses the mesoscale and microscale features of advection fog which occurred over north-eastern side of Japan during summer times. Ka-band radars were installed to investigate time changes of fog areas in horizontal and/or vertical directions. LWC, fog particle size distributions and visibility were also measured. We mainly investigate the evolution process of fog from its formation stage over ocean to advected stage to seashore and further inland by comparing the time change of radar reflectivity. We found several evolution patterns and internal structures. Two distinct patterns of internal structure are uniform type and blob type. The former type tends to occurr over the sea and the latter type tends to occurr over land. We are now further studying their environments such as stability and vertical wind shear. We also compare radar reflectivity with visibility data and try to formulate these two values.