The Physical and Meteorological Characteristics Associated with Lightning Flashes

我们授予NSF ATM-92 13787为期三年的续期，使用来自国家闪电探测网络（NLDN）的数据以及来自雷达和卫星观测的支持信息。我们将同时进行的研究分为两个部分。首先，我们建议继续研究与云对地闪电有关的物理和气象条件。这将包括对以下领域的持续分析：a)美国NLDN闪电记录，包括峰值电流、极性和多样性及其逐年、季节、月与月、风暴与风暴之间以及风暴内部的变化；b)对德克萨斯州中尺度对流复调中的闪电的研究；c)对活跃闪电日的预测；d)冬季闪电的特征。其次，我们将通过确定云对地闪光增加和年平均峰值电流降低背后的原因来调查NLDN的可靠性。我们将使用最近安装的先进闪电测向仪和布鲁克波形数字化记录系统来获取距离德克萨斯农工大学几百公里范围内的闪电波形。我们还建议在德克萨斯州的大学城测量NLDN的检测效率。这项研究将有助于几名研究生的教育，他们将直接参与拟议的研究，其中包括他们在数据采集和分析方面的分享。这项建议包括支持研究生撰写论文和学位论文，并在研讨会和专业会议上展示他们的成果，并撰写描述他们研究的手稿。研究成果将纳入云物理和中尺度现象的高级课程。来自气象系、电子工程系和计算机科学系的本科生将参与其中。

9806189 Orville We grant a three-year continuation of NSF ATM-92 13787 using data from the National Lightning Detection Network (NLDN) with supporting information from radar and satellite observations. There are two parts to the proposed research that we will simultaneously pursue. First, we propose to continue our investigations into the physical and meteorological conditions associated with cloud-to-ground lightning flashes. This will include continued analysis in the following areas, a) NLDN lightning records in the United States, to include peak currents, polarity, and multiplicity and their variation from year to year, with seasons, from month to month, from storm to storm, and within storms, b) research on the lightning in mesoscale convective complexes in Texas, c) the forecasting of active lightning days, and d) the characteristics of winter lightning. Second, we will investigate the NLDN reliability by determining the reasons behind the increased positive flash counts and lowering of the annual mean peak current in cloud-to-ground flashes. We will do this by using a recently installed Advanced Lightning Direction Finder and a Brook waveform digitizing recording system to obtain waveforms on lightning within a few hundred kilometers of Texas A&M University. We propose, also, to measure the detection efficiency of the NLDN at College Station, Texas. This research will contribute to the education of several graduate students who will directly participate in the proposed research, which will include their sharing in data acquisition and analysis. Included in this proposal is support for graduate students who will write theses and dissertations and present their results at seminars and professional meetings, and write manuscripts describing their research. Research results will be incorporated into advanced courses on cloud physics and mesoscale phenomena. Undergraduates will be involved from the Departments of Meteorology, Electrical Engineering, and Computer Science.