Solar Activity Dependence on Lunar Daily Variations of the Ionospheric Total Electron Content Near the Equatorial Anomaly Crest

赤道異常頂峰地區附近之電離層全電子含量之太陰日變化對太陽活動性之依賴性

黃胤年(Yinn-Nien Huang)

《Terrestrial, Atmospheric and Oceanic Sciences》 2卷4期 (1991/12) Pp. 347-354

摘要

本文使用的觀測資料是發生於1982年8月5日18:45(LST)的數個微爆個案。配合JAWS計劃，使用雙都普勒雷達觀測這幾個暴風雨的動能場，動力場，熱力場，以網格距0.25 km的客觀分析方法，計算出相對暴風雨之風速以及回波值，並與先前網格距0.5 km之研究比較。垂直方向由0.25 km至1.25 km分為五層。垂直速度是以非彈性連續方程式，由地表向上積分至邊界層頂。並使用熱力反求法，從以三動量方程式計算出的都普勒風場反推算出壓力與溫度擾動場。結果顯示：以0.5 km為網格尺度所無法見到的某些現象，在0.25 km網格尺度下，非常明顯。更甚者，在此次研究中見到的大部份現象，無論在尺度或外觀上，都令人訝異地遠此前一個使用0.5 km格距時明顯。以雙都普勒雷達計算出的風場的品質與解析度，直接決定了熱力反求技術的成功與否。

並列摘要

Data are presented for several microburst events as they occurred on 5 August1982 at 1845 LST.The kinematic,dyamic,and thermodynamic structures ofthese storms were investigated using dual-Doppler data collected during the JAWSproject.Fields of storm-relative wind and reflectivity were derived using the objective analysis scheme with 0.25 km horizontal grid spacing and compared with aprevious study which used 0.5 km horizontal grid spacing.There were five layersin the vertical ranging from 0.25 to 1.25 km.Vertical velocities were calculatedfrom the anelastic continuity equation by integrating upward from the surface tothe top of the atmospheric boundary layer.The thermodynamic retrieval methodwas employed to retrieve fields of perturbation pressure and temperature from theDoppler derived winds using the three momentum equations.Results show that several features undetected at the 0.5 km grid scale becomeapparent at the 0.25 km grid.Further,most features observed in this study becomestrikingly more apparent both in magnitude and appearance than the earlier studyusing 0.5 km horizontal grid spacing.The quality and resolution of dual-Dopplerderived winds are critical to the success of a thermodynamic retrieval technique.