Radionuclides can provide key information on the temporal dimension of environmental processes, given their well-known rates of radioactive decay and production. Naturally occurring radionuclides, such as 234Th and 210Po, have been used as powerful particle tracers in the marine environment to study particle cycling and vertical export. Since their application to quantify the magnitude of particulate organic carbon (POC) export in the 1990s, 234Th and, to a lesser extent, 210Po have been widely used to characterize the magnitude of the biological carbon pump (BCP). Combining both radionuclides, with their different half-lives, biogeochemical behaviors, and input sources to the ocean, can help to better constrain POC export and capture BCP dynamics that would be missed by a single tracer. Here, we review the studies that have simultaneously used 234Th and 210Po as tracers of POC export, emphasizing what can be learned from their joint application, and provide recommendations and future directions.

中文翻译：

---

联合使用短寿命放射性核素（234Th 和 210Po）作为海洋中下沉粒子的示踪剂


鉴于放射性核素众所周知的放射性衰变和产生速率，它们可以提供有关环境过程时间维度的关键信息。天然存在的放射性核素，如 234Th 和 210Po，已被用作海洋环境中强大的粒子示踪剂，用于研究粒子循环和垂直输出。自 1990 年代应用于量化颗粒有机碳 （POC） 出口量级以来，234Th 和较小程度的 210Po 已被广泛用于表征生物碳泵 （BCP） 的量级。将两种放射性核素及其不同的半衰期、生物地球化学行为和海洋输入源相结合，有助于更好地限制 POC 输出并捕获单个示踪剂会遗漏的 BCP 动力学。在这里，我们回顾了同时使用 234Th 和 210Po 作为 POC 输出示踪剂的研究，强调了可以从它们的联合应用中学到什么，并提供建议和未来方向。