Paleohydroclimate change in Taiwan - unlocking the potential of biomarkers as tracers

Hydroclimate is changing in Taiwan. In 2021, the country experienced the worst drought since 1910. Precipitation and temperature are projected to increase by the end of the century, accompanied by stronger typhoons. Yet, future projection of precipitation, especially its spatial pattern, is rife with uncertainty. Longer hydroclimate records extending beyond the instrumental records may provide context for understanding anthropogenic climate change, as well as the possible range of future change. Over the years, bulk organic matter in marine sedimentary archives have been used to infer land-to-sea transport of carbon and riverine runoff, both of which are tightly linked to hydroclimate change (e.g. typhoons and precipitation) on land. However, given the complex nature of sedimentary composition, the “bulk approach” may be insensitive to changes in the minor components and their shared properties. To better utilize the organic fraction of sediments, this project aims to assess and develop the application of biomarkers as a tracer of terrestrial input to the marine realm, by analyzing a suite of biomarkers, with an emphasis on n-alkanes, branched and hydroxylated glycerol dialkyl glycerol tetraethers, and long chain diols, in marine sediments off Taiwan.