抄録
The survivability of surface drifters deployed by Hydrographic Department for the period from 1988 to 1993 is estimated for two aspects of transmission life and drogue life, and is compared with the drifters deployed within WOCE SVP by other organizations such as the Global Drifter Center operated by Scripps Institution of Oceanography and AOML of NOAA. In comparison of half life which is determined as the time when 50 % drifters survive after deployment, it is concluded that our drifters have provided as robust data set as others from the view point of transmission life and not enough robust in terms of drogue life. The transmission life of our drifters has been getting longer steadily since 1988 and reached close to 300 days in 1993.
Two reasons that regulate the drifter life; accidental troubles happening on drifters and the life of battery, and their effects on the characteristics of survivability are also discussed. It is suggested to be possible to describe the survivability of surface drifters by using a simplified model where only two components mentioned above are taken into account.
