Cave Ventilation and Dripwater Geochemistry: Modern Time Series Speleothem Paleoproxy Calibration

该研究小组的目标是研究洞穴空气动力学和滴水化学，以更好地了解洞穴沉积物如何生长，以及它们如何将古气候信号纳入方解石带。 这项研究补充了正在进行的监测活动建立在空心岭洞（HRC），玛丽安娜，佛罗里达。作为正在进行的努力的一部分，研究人员已经能够建立一个简单的模型，用于洞穴与外部空气的空气交换，从而确定二氧化碳在洞穴呼吸时进出的速率。 这是通过连续测量222 Rn（氡气）、二氧化碳、温度、大气压、相对湿度来实现的（现场空气密度）、降雨量（洞穴滴水率），风速和风向（洞穴气流），通过扩大这一阵列的原位洞穴监测仪器，以确定高分辨率的三维和时间的空气和水（滴）流和化学通过洞穴（水力学），研究人员的目的是提供一个更好的理解的过程和环境控制使用洞穴作为古气候代理。 实际上，研究小组将校准保存在？现代？研究人员计划进行几项具体的实验，包括：（1）部署密集的微型温度和气流传感器阵列，以绘制通风图;（2）测量现有的活性石笋的生长速度和同位素及微量元素成分;（3）测量现有的活性石笋的生长速度和同位素及微量元素成分;（4）测量现有的活性石笋的生长速度和同位素及微量元素成分。（3）分析雨水和滴水的化学和同位素组成（4）进行底栖生物通量实验以确定222 Rn从石灰岩壁和滴注物进入洞穴的速率：（5）确定洞穴内部可交换空气量;主要的更广泛的影响包括对广泛使用的气候代用指标的局限性和实用性的更好理解的潜力，以及本科生和研究生的支持。

The research team aims to study cave aerodynamics and dripwater chemistry to better understand how speleothems grow and how they incorporate paleoclimate signals into their calcite bands. This research complements an ongoing monitoring campaign established in Hollow Ridge Cave (HRC), Marianna, Florida. As part of ongoing efforts, the researchers have been able to establish a simple model for cave air exchange with outside air and, thus, the rate of carbon dioxide ventilation in and out of this cave as it breathes. This has been achieved by continuously measuring 222Rn (radon), carbon dioxide, temperature, barometric pressure, relative humidity (in situ air density), rainfall (cave drip rates), wind speed and direction (cave air flow), and solar irradiance.By expanding this array of in situ cave monitoring instruments to determine high resolution 3D and temporal air and water (drip) flow and chemistry through the cave (hydraulics), the researchers aim to provide a better understanding of the processes and environmental controls on using speleothems as paleoclimate proxies. In effect, the research team will calibrate the isotopic and chemical signals preserved in ?modern? calcite precipitated in a well-understood cave with the isotopic and chemical signatures in the cave air and drip.The researchers plan several specific experiments that include: (1) deploying a dense array of micro-scale temperature and air flow sensors to map ventilation; (2) measuring existing active stalagmites for growth rates and isotopic and trace element compositions; (3) analyzing rainwater and drip water for chemistry and isotopic composition (time series); (4) running benthic flux experiments to establish rates of 222Rn emanation into the cave from limestone walls and drips; (5) establishing internal exchangeable cave air volume; (6) dye-chasers to estimate the epikarst volume and flow patterns; and (7) hydraulic groundwater gradients around the cave.The primary broader impacts involve the potential for improved understanding of the limitations and utility of a widely used climate proxy and the support of undergraduate and graduate students.