Collaborative Research: Submersible Humidity Sensor research and development for measuring surface air humidity and evaporative flux on autonomous ocean floats

水蒸气是地球上最强大和变化最大的温室气体，是地球降水和大气中凝结潜热的来源。卫星很难观测到湿度。由于经久耐用的传感器和观测平台的成本，无法对地面空气湿度进行准确的海洋观测。为低成本无人值守的海洋浮标开发潜水式湿度传感器，将能够在更多地点更准确地测量空气表面湿度和蒸发量。更准确的湿度测量将减少蒸发和大气-海洋热量收支中的最大误差。来自潜水浮标的湿度测量将改善从季节性到亚季节性时间尺度的天气预报。具体地说，对热带气旋(飓风)附近的船员船只来说，在太偏远或太危险的情况下进行测量，将改善热带气旋强度预测，拯救生命和财产。该项目将开发和测试一种坚固的潜水式表面空气湿度传感器，并将其集成到标准的自主海洋剖面浮标中。研究人员将与经过验证的观测系统一起测试湿度传感器，以表征其在各种天气条件下的准确性和误差。这项研究将评估浮出水面的海洋漂浮物的测量结果的代表性。这项研究将确定散装空气动力学公式中使用湿度观测值估算蒸发量的准确性。这项研究将探索在湿式温度计上测量的温度瞬变是否可以作为测量蒸发通量的替代方法。湿度传感器的开发增强了“海洋科学研究界的观察、实验或分析能力”，以响应海洋技术和跨学科协调计划的目标。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Water vapor is Earth’s most potent and variable greenhouse gas, the source of its precipitation, and of its latent heat of condensation in the atmosphere. Humidity is poorly observed by satellites. Accurate marine observations of surface air humidity are prohibited by the cost of durable sensors and observing platforms. Development of a submersible humidity sensor for low-cost unattended ocean floats will allow measurement of air surface humidity and evaporation more accurately and in more locations. More accurate humidity measurements will reduce the largest error in evaporation and atmosphere-ocean heat budgets. Humidity measurements from submersible floats will improve weather forecasting on seasonal to subseasonal time scales. Specifically, measurements in conditions too remote or too dangerous for crewed vessels near tropical cyclones (hurricanes) will improve tropical cyclone intensity forecasts, saving life and property. This project is to develop and test a robust submersible surface air humidity sensor and integrate it into standard autonomous ocean profiling floats. The researchers will test the humidity sensor alongside proven observing systems, characterizing its accuracy and error in various weather conditions. The research will assess the representativeness of measurements from surfacing ocean floats. The research will determine the accuracy of evaporation estimates using humidity observations in bulk aerodynamic formulae. The research will explore whether temperature transients measured at a wet thermometer can be used as an alternative method for measuring evaporative flux. The development of the humidity sensor enhances “observational, experimental or analytical capabilities of the ocean science research community,” in response to goals of Ocean Technology and Interdisciplinary Coordination program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.