Performance of Humidity Measurement with Sensor Protection Using Gore-Tex Fabric

A measure of moisture content in the air, humidity, is critical to study the air-sea interaction and essential to estimate turbulent heat exchange through the sea surface. However, humidity is difficult to observe over the sea because its sensor is easily damaged by seawater immersion. Therefore, we protected air temperature/relative humidity sensors from seawater immersion using commercially available Gore- Tex fabric, attached them to an uncrewed surface vehicle, aka a Wave Glider, and observed humidity in the region east of the Sanriku coast, Japan, together with other meteorological and oceanographic parameters. To examine the performance of humidity measurement by sensors protected with Gore- Tex fabric, we conducted intercomparison experiments between sensors with and without Gore- Tex fabric for several days before Wave Glider observations over the actual sea and in a thermo-hygrostat chamber. Here, we report the results of the examinations.