Sediment trap record of alkenones from the East Sea (Japan Sea)

Lee, K. E.*; Khim, B.-K.*; Otosaka, Shigeyoshi  ; Noriki, Shinichiro*

Long chain (C) alkenones in sinking particles obtained from the northeastern and the southern regions of the Japan Sea were examined to investigate the characteristics of production, export, and degradation of organic materials in the water column. A comparison of alkenone temperatures with satellite sea surface temperatures (SST) revealed that the alkenone temperatures were higher (6-13 C) than SST during winter time, and lower (2-5 C) during summer time. It indicated that there was a time lag between the SST and the trap records (about 3 months in winter and 1 month in summer). But, the annual average alkenone temperatures are close to annual average SST in the Yamato Basin. The reasons for this time lag can be (1) subsurface production of alkenones in summer and (2) slow settling velocity and long residence time of alkenones in the upper water column especially during winter time.