Holocene hydroclimatic variability recorded in sediments from Maddox Lake (northern California Coast Range)
Holocene hydroclimatic variability recorded in sediments from Maddox Lake (northern California Coast Range)
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DOI：
10.1017/qua.2023.18
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发表时间：
2023-05-04
影响因子：
2.3
通讯作者：
Ramezan, Reza
中科院分区：
文献类型：
--
作者：
Kirby, Matthew;Barbosa, Jazleen;Ramezan, Reza
利用湖泊沉积物对过去气候的看法对于评估现代和未来的气候变化至关重要。这些观点对于美国西部等水资源紧张地区尤为重要。其中一个这样的地区是西北部的加州（CA），那里的全新世长度水文气候记录是稀缺的。在这里，我们提出了一个9000年，相对湖水位记录马多克斯湖（CA）使用多指标的方法。早全新世的特点是湖泊水位较低，并短暂地转向较潮湿的气候/相对高水位。8.4-8.06 cal ka BP，可能与8.2 ka冷事件和大西洋经向翻转环流（AMOC）的变化有关。从5.2-0.55 cal ka BP，马多克斯湖经历了长期的回归，跟踪的变化，在夏季和冬季日照，热带和东北太平洋SST，和南迁移的ITCZ。这种逐渐的回归在中世纪气候异常（MCA）期间达到了一个明显的相对低点。MCA之后是一个明显的相对高位，与小冰期相关。后者反映了对北大西洋火山活动、太阳变化以及AMOC和北极海冰范围可能变化的远场响应。我们的研究结果进一步证实了西北部加州的水文气候敏感性的各种强迫，包括那些来自北大西洋。
Perspectives on past climate using lake sediments are critical for assessing modern and future climate change. These perspectives are especially important for water-stressed regions such as the western United States. One such region is northwestern California (CA), where Holocene-length hydroclimatic records are scarce. Here, we present a 9000-year, relative lake level record from Maddox Lake (CA) using a multi-indicator approach. The Early Holocene is characterized by variably low lake levels with a brief excursion to wetter climates/relative highstand ca. 8.4-8.06 cal ka BP, possibly related to the 8.2 ka cold event and changing Atlantic Meridional Overturning Circulation (AMOC). From 5.2-0.55 cal ka BP, Maddox Lake experienced a long-term regression, tracking changes in summer-winter insolation, tropical and northeast Pacific SSTs, and the southward migration of the ITCZ. This gradual regression culminated in a pronounced relative lowstand during the Medieval Climatic Anomaly (MCA). A marked relative highstand followed the MCA, correlative to the Little Ice Age. The latter reflects a far-field response to North Atlantic volcanism, solar variability, and possibly changes in AMOC and Arctic sea ice extent. Our results further confirm the hydroclimatic sensitivity of northwest California to various forcings including those emanating from the North Atlantic.