Temperature and productivity influences on U37K′ and their possible relation to solar forcing of the Mediterranean winter

摘要: To assess the extent and nature of human-induced climate change, we need to understand natural variability. This heavily relies on proxy-based reconstructions, calling for excellent understanding conditions represented by proxies. Here report an alkenone-based (U37K′) sea surface temperature (SST) proxy record originating from south Italian marine sediments, covering 1305 A.D. 1979 with a 3.87 year resolution. The shallow-water cores, extracted Gallipoli terrace in Gulf Taranto, were dated Torino group high accuracy over last two millennia, using radiometric tephroanalysis methods. On basis comparison historical satellite-derived productivity data, propose that U37K′ reflects mainly SST cooler part is modified variation magnitude timing peak alkenone production seasonal cycle. Comparison atmospheric Δ14C, solar energy variability, shows correlation (r = −0.73) period between 1420 before human interference Δ14C combustion fossil carbon release radioactive isotopes nuclear tests. suggests centennial-scale forcing. We wind-induced mixing resulting Mediterranean dynamics plays crucial role translating activity during year.