The Madden-Julian Oscillation (MJO) is the most prominent mode of intraseasonal variability in the tropics which is responsible for much of the observed intraseasonal climate variance not only there but also in higher latitudes. The short time-span of modern instrumental data limits our understanding of the MJO and obtaining MJO information from natural archives could extend this greatly. Here a Giant Clam shell (Tridacna spp.) with a life span about two years (from January 29, 2012 to December 9, 2013) was collected from the northern South China Sea, in the western Pacific. Several daily to hourly resolution biological and geochemical proxy records, including the daily growth rate, hourly Fe/Ca, Sr/Ca and fluorescence intensity, were developed to compare these with local weather/climate records. Spectral analyses suggested that these ultra-high resolution proxy records can clearly record MJO variability in the tropics. The substantial connection between the proxy records and MJO possibly linking through the local effective solar radiation, SST, precipitation and wind speeds. This is the first record of the MJO signal in a natural paleoclimate archive. Our findings provide new insights to study the MJO beyond the instrumental records, and since fossil Tridacna shells from different geological times can be used to investigate the MJO under various climate conditions.

Madden-Julian涛动（MJO）是热带地区季节内变化的最主要模式，这不仅在该地区而且在较高纬度地区也造成了许多观测到的季节内气候变化。现代仪器数据的时间跨度短，这限制了我们对MJO的理解，从自然档案中获取MJO信息可以大大扩展这一范围。这里是一个巨型蛤壳（Tridacna寿命约为两年（从2012年1月29日至2013年12月9日）是从南太平洋北部的南太平洋海中采集的。建立了一些每日至每小时解析的生物和地球化学代理记录，包括每日增长率，每小时Fe / Ca，Sr / Ca和荧光强度，以将其与当地天气/气候记录进行比较。光谱分析表明，这些超高分辨率代理记录可以清楚地记录热带地区MJO的变化。代理记录和MJO之间的实质联系可能通过当地有效的太阳辐射，SST，降水和风速联系在一起。这是自然古气候档案中MJO信号的第一条记录。我们的发现提供了新的见解，以研究仪器记录之外的MJO，以及化石以来来自不同地质时期的Tridacna贝壳可用于研究各种气候条件下的MJO。