Abe Osamu, Agata Seizen, Morimoto Maki, Abe Manabu, Yoshimura Kei, Hiyama Tetsuya, Yoshida Naohiro
Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan.
Isotopes Environ Health Stud. 2009 Sep;45(3):247-58. doi: 10.1080/10256010903083847.
We produced continuous records of sea surface salinity and isotopic composition from 1998 to 2004 at Ishigaki Island, southwest Japan, and found clear seasonal variations in salinity and oxygen isotopic composition and increasing trends of them after 1999. These increasing trends could be principally due to the decreasing difference between local precipitation (P) and evaporation (E), as a result of the reduction of horizontal vapour transport from adjacent oceans. When samples collected in heavy rainfall events were excluded, the average Deltadelta(18)O/Delta salinity slope was obtained as 0.31, 0.35 in summer and 0.28 in winter. Estimated E/P ratios based on the isotopic box model are in good agreement with the ratios of independently estimated E to observed P.
我们于1998年至2004年在日本西南部的石垣岛制作了海面盐度和同位素组成的连续记录，发现盐度和氧同位素组成存在明显的季节性变化，并且在1999年之后它们呈上升趋势。这些上升趋势主要可能是由于来自相邻海洋的水平水汽输送减少，导致当地降水量（P）与蒸发量（E）之间的差异减小。当排除暴雨事件中采集的样本时，夏季的平均δδ(18)O/δ盐度斜率为0.31，冬季为0.35，夏季为0.28。基于同位素箱模型估算的E/P比值与独立估算的E与观测到的P的比值高度一致。
