Abstract The variability of El Nino-Southern Oscillation (ENSO) on centennial to millennial time-scales is poorly understood due to the insufficient length, continuity, or resolution of existing paleoclimate records. Here we present a new, continuous, sub-annually resolved scanning XRF Ti record from marine sediments collected from Santa Barbara Basin (SBB) to reveal interannual precipitation changes in Southern California for the past 9000 yrs. Interannual precipitation variability in Southern California is closely related to ENSO through an atmospheric teleconnection with the tropical Pacific. Thus, Southern California precipitation reconstructions provide an opportunity to explore ENSO variability through time. Wavelet analysis of the SBB Ti record demonstrates interannual (2–7 yrs) precipitation variance was relatively weak prior to 4.4 ka, and significantly increased after 4.4 ka. Our record demonstrates a relationship between Southern California precipitation and the tropical Pacific and extratropical climate. The inferred increase of ENSO variability during the late Holocene is generally consistent with the published tropical Pacific ENSO records, and could be associated with a southward shift of the Intertropical Convergence Zone (ITCZ). Meanwhile, a deeper, westward-shifted Aleutian Low after 4.4 ka may have strengthened the ENSO teleconnection between the tropical Pacific and Southern California, contributing to the amplified interannual precipitation variance in the SBB record. Community Earth System Model (CESM) simulations through the Holocene (0, 3, 6, 9 ka) support the role of both the ITCZ and the AL in the enhancement of interannual precipitation variability in Southern California.

中文翻译：

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南加州高分辨率年际降水重建：对全新世 ENSO 演化的影响

摘要 由于现有古气候记录的长度、连续性或分辨率不足，人们对厄尔尼诺 - 南方涛动 (ENSO) 在百年到千年时间尺度上的变异性知之甚少。在这里，我们从圣巴巴拉盆地 (SBB) 收集的海洋沉积物中展示了一个新的、连续的、次年分辨率的扫描 XRF Ti 记录，以揭示南加州过去 9000 年的年际降水变化。通过与热带太平洋的大气遥相关，南加州的年际降水变率与 ENSO 密切相关。因此，南加州降水重建提供了一个探索 ENSO 随时间变化的机会。SBB Ti 记录的小波分析表明，年际（2-7 年）降水变化在 4.4 ka 之前相对较弱，并在 4.4 ka 后显着增加。我们的记录显示了南加州降水与热带太平洋和温带气候之间的关系。推断的全新世晚期 ENSO 变率的增加与公布的热带太平洋 ENSO 记录基本一致，并且可能与热带辐合带 (ITCZ) 的南移有关。与此同时，在 4.4 ka 之后更深的、向西移动的阿留申低压可能加强了热带太平洋和南加州之间的 ENSO 遥相关，导致 SBB 记录中年际降水变化的放大。社区地球系统模型 (CESM) 模拟通过全新世 (0, 3, 6,