| dc.description.abstract | The temperature structure parameter (C_T^2) is often used to quantify the intensity of the turbulence. Measuring the temperature variation can calculate C_T^2 in the horizontal space, and it can represent the environmental instability to analyze the structural changes of atmospheric turbulence. In recent years, in-situ atmospheric observation has been developed towards high temporal resolution, but the observation of environmental turbulence is still lacking, which is mainly limited by expensive instruments and difficult maintenance. In order to strengthen the understanding of the temporal and spatial distribution characteristics of turbulence in Taiwan. This research developed a set of temperature structure parameter measurement technology that is cost-effective, using a thermocouple with a high-precision analog measurement system. The sample rate we use 60Hz to measure 1.5m differential temperature. To solve C_T^2 function, the temperature difference between the distances are normalized by the 2/3 law (Kolmogorov, 1941). The new insturement we call the Mirco-Thermometer.
The development of the Mirco-Thermometer has gone through a series of validation processes. In the laboratory control experiment, we found that the measured value obtained by the instrument has a good linear relationship with the control temperature difference. Testing the observed C_T^2 under stable conditions as the base value of the stability of the atmospheric disturbance instrument. In this study, this instrument was further applied to the real atmospheric environment, and two sets of observational experiment data were established.
The first experiment is in NAHO (NCU Atmospheric and Hydrological Observatory) station. The Mirco-Thermometer was mounted at heights of 2, 8, 16 and 32 meters, through vertically layered observation, this experiment explores the characteristics of the near-surface environmental instability and dirual cycle at NAHO station. The second group of experiments is a part of field campaign in the 2021 Yilan Experiment of Servere Rainfall (2021 YESR). Three sets of atmospheric thermal turbulence measurement systems are installed in Sansing Township and Datong Township, Yilan County. In this spatial deployment at plain and mountain area, helps to explain the temporal and spatial interaction between rainfall and the occurrence of near-surface atmospheric turbulence. Overall, the C_T^2 obtained by the Mirco-Thermometer developed in this study can correspond to the characteristics of atmospheric instability and explain the changes in the turbulent flow. It can provide forecasts of very short-term rainfall precursor. For the future application, the instrument can be used onboard an unmanned aerial vehicle to measure the three-dimensional distribution and characteristics of atmospheric turbulence under different weather systems. | en_US |