Historical February Sea-Surface Temperature Estimates Utilising Diatom Transfer Functions with Core MD88-787

The purpose of this study was to estimate past sea-surface temperature in the Southeast Indian Ocean. The accumulation of diatom microplankton assemblages in sediments being the proxy for these records of climatic change. A transfer function is a mathematical method that allows quantitative estimations of environmental parameters from past biogenic sedimentation. In this study, a diatom transfer function was established to relate biological species to selected environmental parameter of the ocean (sea-surface temp). These equations were then employed on observed fossil species from core samples to provide quantitative estimates of sea-surface temperature.Estimates of sea-surface temperature are given here based on the assemblages of diatoms found in core MD88-787. The information provided gives the extrapolated age-scale through the core, and two estimates of feb SST based on different diatom transfer functions (DTF 109/24/6 and DTF 166/34/4). It is probable that the 'real' SST signal lies between the model estimates. The model diagnostics and lower number of non-analogue events from DTF 109/24/6 over that of results produced by DTF 166/34/4 suggest that SST estimates are closer to those provided by the former model.

本研究旨在重建东南印度洋的古海表温度（sea-surface temperature）。沉积物中硅藻微浮游生物组合的堆积量，可作为此类气候变化记录的代用指标（proxy）。转换函数（transfer function）是一类可基于古生物沉积记录定量反演环境参数的数学方法。本研究构建了硅藻转换函数，以建立生物物种与选定的海洋环境参数（海表温度）之间的定量关联。随后将该函数应用于岩芯样品中的化石物种观测数据，以定量估算古海表温度。
本次公开的海表温度估算结果，基于岩芯MD88-787中发现的硅藻组合得出。所提供的数据集包含该岩芯的外推年代标尺，以及基于两种不同硅藻转换函数（DTF 109/24/6与DTF 166/34/4）得到的两次feb海表温度估算结果。推测真实的海表温度信号大概率介于两个模型的估算结果之间。相较于DTF 166/34/4的结果，DTF 109/24/6的模型诊断性能更优，且无现代相似类群事件（non-analogue events）的数量更少，表明该模型得到的海表温度估算结果更为贴近真实值。