An 1800-year oxygen-isotope record of short- and long-term hydroclimate variability in the northern neotropics from a Jamaican marl lake
An 1800-year oxygen-isotope record of short- and long-term hydroclimate variability in the northern neotropics from a Jamaican marl lake
复制标题
DOI：
10.1016/j.quascirev.2022.107930
复制
发表时间：
2023-02
影响因子：
4
通讯作者：
J. Holmes;Michael J. Burn;L. Cisneros-Dozal;Matthew Jones;S. Metcalfe
中科院分区：
文献类型：
--
作者：
J. Holmes;Michael J. Burn;L. Cisneros-Dozal;Matthew Jones;S. Metcalfe
多年尺度上的水文气候变率一直是环加勒比地区共同纪元的一个显著特征，特别是在公元800-950年期间，与终末经典期相一致，（所谓的终端经典干旱：TCD）在中美洲，并与小冰河时代约1500至1800 CE，与复杂的海洋-大气相互作用。先前的古气候重建汇编揭示了一个明确的降水偶极子之间的北方和中美洲南部的共同时代，这是符合气象数据和模拟实验。然而，该地区其他地方的变化模式还不太清楚，尽管古气候记录确实指出了空间的复杂性。在这里，我们提出了一个100分之十年尺度的湖泊沉积物水文气候重建的基础上介形虫壳稳定同位素从Wallywash大池塘，牙买加，涵盖了过去的1800年，填补了该地区的记录的空间空白。δ 18 O值的变化在这个网站是一个代理的有效水分的变化，他们揭示了一个显着的湿相在终端经典期（TCP），这表明降水偶极子在北方和中美洲南部可能有一个东向西的组成部分。这一点得到了以前一些研究的支持，尽管需要在该地区的战略地点提供更多的地点来证实这一点。Wallywash的小冰期间隔比TCP干燥，尽管信号不如更广泛区域内的某些站点清晰，这表明水文气候的区域复杂性也表征了该间隔。
Hydroclimate variability on multi-decadal timescales has been a prominent feature of the circum-Caribbean region over the common era, with marked dry intervals noted in particular for the period 800–950 CE coinciding with the Terminal Classic Period (the so-called Terminal Classic Drought: TCD) in Mesoamerica, and with the Little Ice Age from about 1500 to 1800 CE, linked to complex ocean-atmosphere interactions. Previous compilations of palaeoclimate reconstructions have revealed a clear precipitation dipole between northern and southern Mesoamerica over the common era, which is consistent with meteorological data and modelling experiments. However, patterns of variability elsewhere within the region are less well understood, although palaeoclimate records do point to spatial complexity. Here, we present a ∼sub-decadal-scale lake-sediment hydroclimate reconstruction based on ostracod-shell stable isotopes from Wallywash Great Pond, Jamaica, covering the past ∼1800 years, which fills a spatial gap in records for the region. Variations in δ18O values at this site are a proxy for changes in effective moisture and they reveal a marked wet phase over the Terminal Classic Period (TCP), suggesting that the precipitation dipole over northern and southern Mesoamerica may have an east to west component. This is supported by some previous studies, although additional sites are required from strategic localities within the region to confirm this. The Little Ice Age interval at Wallywash is drier than the TCP, although the signal is less clear than at some sites within the wider region, suggesting that regional complexity in hydroclimate has characterised this interval as well.