Abstract. To investigate the sensitivity of evaporation to changing longwave radiation we developed a new experimental facility that locates a shallow water bath at the base of an insulated wind tunnel with evaporation measured using an accurate digital balance. The new facility has the unique ability to impose variations in the incoming longwave radiation at the water surface whilst holding the air temperature, humidity and wind speed in the wind tunnel at fixed values. The underlying scientific aim is to isolate the effect of a change in the incoming longwave radiation on both evaporation and surface temperature. In this initial paper we describe the configuration and operation of the system and outline the experimental design and approach. We then evaluate the thermodynamic properties of the new system and demonstrate that the evaporation, air temperature, humidity and wind speed are measured with sufficient precision to support the scientific aims. We find that the shallow water bath naturally adopts a steady state temperature that closely approximates the thermodynamic wet bulb temperature.

中文翻译：

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评估风洞，旨在研究蒸发对水面入射长波辐射变化的响应。一、热力学特性

摘要。为了研究蒸发对变化的长波辐射的敏感性，我们开发了一种新的实验装置，该装置在绝缘风洞底部放置一个浅水浴，并使用精确的数字天平测量蒸发。新设施具有独特的能力，可以在将风洞中的空气温度、湿度和风速保持在固定值的同时，改变水面的入射长波辐射。潜在的科学目标是分离入射长波辐射变化对蒸发和地表温度的影响。在这篇初始论文中，我们描述了系统的配置和操作，并概述了实验设计和方法。然后我们评估新系统的热力学性质并证明蒸发，空气温度、湿度和风速的测量精度足以支持科学目标。我们发现浅水浴自然采用稳态温度，该温度非常接近热力学湿球温度。