Introduction

Atmospheric boundary layer (ABL) plays an important role in long range transport of pollutants over the sea. Lidar enables us to infer both spatial and temporal data of ABL structure. Since 1984, the group has developed the system and number of observations were conducted over the ocean and coastal region under various meteorological conditions. This data base consists of campaign data around Japan and periodic data obtained at Ship Research Institute in Tokyo. In 1986, profiles of exhaust gas plumes were observed. The ship board experiments were conducted in 1991 from Ise wan to Niijima, in 1992 along the coastal zone of Japan, in 1993 in the west of Pacific Ocean, in 1994 near Okinawa, In 1995, at Oki islands when cold-air out blows and convective plumes were observed.