【摘要】 本文介绍了HEIFE近地层观测中应用的大气湍流数据的采集和处理系统。由于采用了较新的微机技术和适当的软件,本系统耗资较低,并实现了外场大量观测数据的实时处理。观测所用的大气湍流传感器包括三维超声风速温度计和红外湿度计等;数据采集和处理中考虑了必要的传感器修正,并利用涡旋相关方法求得近地层各主要量的湍流通量和其他统计特征量,包括各二阶、三阶矩及有关量的功率谱和协谱分布。检查表明,该系统工作可靠,所获数据具有较高质量。更多还原

【Abstract】 A micro-computer controlled turbulence data acquisition and processing system has been developed for the Program on Atmosphere-Land Surface Processes in Heihe River Basin(HEIFE). The turbulence sensors are mainly a 3-D sonic anemo-thermometer (Kaijo-Denki DAT-300) for wind and temperature, and an infrared hygrometer and the associated Humicap sensor(Kaijo-Denki, AH-300) for humidity measurements. Sometimes a 12μm tungsten wire thermometer and a fine wire(80μm) thermocouple psychrometer are also used in measuring temperature and humidity fluctuations. The proper facing of the sonic anemometer is adjusted by an Emotator; the tilt angle of its vertical component is checked carefully and recorded through a Clinometer. 8 to 12-channel signals, after active 10 Hz low pass filters, are transferred to a 12-bit A/D converter, and then, an IBM PC compatible computer. In most cases data is sampled at 10 Hz during 30 to 45-minute runs. Wind, temperature, and humidity fluctuation signals are visually displayed on the screen, which supplies a feature of real-time monitoring on the original data series.With well-done software the data could be processed within 10 minutes after each run, including eddy correlation calculations and spectra analysis, with paper printing or data file output of the concerned statistical quantities, such as means, variances, correlations, stability parameter, momentum, heat, and water vapor fluxes, and the power spectra of wind components, temperature, specific humidity, and the cospectra of momentum and heat flux, etc.. Some proper treatments for the original time series, such as despiking, detrending, and some corrections; to the sensor probes are also appropriately considered in the data processing procedure.As checked by the analyzed results, the turbulence data collected are of high quality. This system and the associated data processing software form a good basis for the turbulence measurements in HEIFE Intensive Observation Periods.更多还原