## 1 Introduction  
Bad weather such as typhoons, blizzards, and freezing rain will bring huge disasters to human beings. It is of great significance to study its genesis and evolution mechanism. In the early warning observation of typhoon disasters, every 1 km of typhoon track forecast error can reduce losses by USD 20 million, and every 1 m/s reduction in intensity forecast error can reduce losses by USD 100 million [1, 2]. The refined detection of severe weather in the inner core area is an important means to predict its intensity and development trend [3, 4]. As a key parameter to determine the duration of a typhoon, high-performance measurement of humidity in the inner core region is particularly important [5, 6]. The internal environment of severe weather is complex, with wind speeds as high as 50 m/s, and temperature and air pressure as low as \(-90\,^{\circ}\)C and 10 hPa [7, 8, 9, 10]. On the one hand, freezing temperatures and sudden changes in air pressure will cause the sensor to condense and repeatedly freeze [11], adding massive interference to the sensor measurement. We urgently need to improve the sensitivity of the sensor to detect weak changes in the sensor in extreme environments and reduce measurement errors. On the other hand, extremely high wind speeds and drastic changes in the background also put high requirements on the dynamic performance of the sensor [12; 13; 14]. The state of the environment is constantly changing, and we need sensors that can respond in real-time to sudden changes in the background to obtain all the conditions of the environment and ensure the comprehensiveness of detection. Therefore, it is essential to simultaneously improve sensors' static sensitivity and dynamic response performance in complex environments. Humidity sensors mainly include capacitive [15; 16], resistive [17], piezoresistive [18; 19], resonant [20], and fiber-optic [21; 22] components. As the main research object and commercial product [23; 24; 25; 26; 27], the capacitive humidity sensor has the advantages of high sensitivity, fast response speed, good product interchangeability, and easy integration. In the humidity measurement process of capacitive sensors, the adsorption of water molecules by the humidity sensitive medium will cause the dielectric constant to change and thus the capacitance value to change. Capacitive structures of sensitive sensing units include sandwich type [28] and interdigital type [29]. The two electrodes of the sandwich capacitor are facing each other, and the moisture-sensitive film is located between the electrodes, which has high sensitivity and slow dynamic response. The electrodes of the interdigital capacitor are in the same plane, and the surface of the electrode is covered with a moisture-sensitive film, which has low sensitivity and a fast dynamic response. To improve the sensitivity and dynamic response performance of humidity sensors in extreme environments, researchers have made a lot of technical research. In 2014, [PERSON] designed a sandwich capacitive humidity sensor with a heater, which solved the sensor condensation problem by heating. At the same time, the measurement circuit is designed according to the characteristics of the humidity sensor and ground experiments, and the results show that the humidity sensitivity is about 2.3 pF/%RH [30]. In 2016, [PERSON] proposed an interdigitated humidity sensor that uses ZnO nanorods to make a moisture-sensitive film and found that the thinning of the spacing of ZnO nanorods will reduce the density of the moisture-sensitive film and speed up the response speed [31]. In 2017, [PERSON] studied a sandwich capacitive humidity sensor with a grid-shaped top plate. The numerical results show that the response time of the microhole upper electrode sensor is 86% better than that of the grid upper electrode sensor. The response time of the humidity sensor can be improved by reducing the hole spacing, increasing the aperture, reducing film thickness, and reasonably enlarging the porosity of the film [32].