On the timing between terrestrial gamma ray flashes, radio atmospherics, and optical lightning emission

On 25 October 2012 the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) and the Tropical Rainfall Measuring Mission (TRMM) satellites passed over a thunderstorm on the coast of Sri Lanka. RHESSI observed a terrestrial gamma ray flash (TGF) originating from this thunderstorm. Optical measurements of the causative lightning stroke were made by the lightning imaging sensor (LIS) on board TRMM. The World Wide Lightning Location Network (WWLLN) detected the very low frequency (VLF) radio emissions from the lightning stroke. The geolocation from WWLLN, which we also assume is the TGF source location, was in the convective core of the cloud. By using new information about both RHESSI and LIS timing accuracy, we find that the peak in the TGF light curve occurs 230 $\mu$s before the WWLLN time. Analysis of the optical signal from LIS shows that within the uncertainties, we cannot conclude which comes first: the gamma emission or the optical emission. We have also applied the new information about the LIS timing on a previously published event by {\O}stgaard et al. (2012). Also for this event we are not able to conclude which signal comes first. More accurate instruments are needed in order to get the exact timing between the TGF and the optical signal

Effects of Lightning on Trees: A Predictive Model Based on in situ Electrical Resistivity

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology also were important; the heating density of a hypothetical 10 m tall Alseis blackiana was 49 times greater than for a 30 m tall conspecific, and 127 times greater than for a 30 m tall Dipteryx panamensis. Lianas may protect trees from lightning by conducting electric current; estimated heating and maximum power were reduced by 60% (±7.1%) for trees with one liana and by 87% (±4.0%) for trees with three lianas. This study provides the first quantitative mechanism describing how differences among trees can influence lightning–tree interactions, and how lianas can serve as natural lightning rods for trees

Evaluation of the Performance Characteristics of the Lightning Imaging Sensor

The Lightning Imaging Sensor (LIS) that was on board the Tropical Rainfall Measuring Mission (TRMM) satellite captured optical emissions produced by lightning. In this work, we quantify and evaluate the LIS performance characteristics at both the pixel level of LIS events and contiguous clusters of events known as groups during a recent 2-yr period. Differences in the detection threshold among the four quadrants in the LIS pixel array produce small but meaningful differences in their optical characteristics. In particular, one LIS quadrant (Q1, X >= 64; Y >= 64) detects 15%-20% more lightning events than the others because of a lower detection threshold. Sensitivity decreases radially from the center of the LIS array to the edges because of sensor optics. The observed falloff behavior is larger on orbit than was measured during the prelaunch laboratory calibration and is likely linked to changes in cloud scattering pathlength with instrument viewing angle. Also, a two-season comparison with the U.S. National Lightning Detection Network (NLDN) has uncovered a 5-7-km north-south LIS location offset that changes sign because of periodic TRMM yaw maneuvers. LIS groups and flashes that had any temporally and spatially corresponding NLDN reports (i.e., NLDN reported the radio signals from the same group and/or from other groups in the same flash) tended to be spatially larger and last longer (only for flashes) than the overall population of groups/flashes.NASA [80MSFC17M0022]; NASA ROSES-2014 program [NNH14ZDA001N-WEATHER]6 month embargo; published online: 6 June 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

PENGARUH MOTIVASI TERHADAP EFEKTIVITAS KERJA PEGAWAI DI KECAMATAN LENGKONG KOTA BANDUNG

Penelitian ini didasarkan pada masalah pokok, yaitu Efektivitas kerja pegawai rendah. Hal ini disebabkan oleh kurangnya motivasi kerja pegawai. di Kecamatan Lengkong Kota Bandung Pendekatan dalam penelitian ini tentang Motivasi dan Efektivitas Kerja Pegawai dilihat dari kontek kebijakan publik dan administrasi publik. Metode penelitian yang digunakan, metode explanatory survey. Metode ini digunakan untuk menjelaskan fenomena sosial yang dalam hal ini digunakan untuk meneliti pengaruh Motivasi (X) sebagai variabel bebas terhadap Efektivitas Kerja Pegawai (Y) sebagai variabel terikat. Penelitian ini menggunakan analisis kuantitatif melalui penggunaan metode analisis jalur (path Analysis) yang dimaksudkan untuk mengetahui besaran pengaruh variabel Motivasi terhadap Efektivitas Kerja Pegawai di Kecamatan Lengkong Kota Bandung. Teori penghubung yang digunakan dalam membahas Langkah-langkah Motivasi dan Efektivitas Kerja Pegawai digunakan teori Sistem Kompensasi, implementasi sistem kompensasi sebagai penghargaan atas prestasi kerja pegawai juga sebagai alat untuk memotivasi kerja memberikan kontribusi positif terhadap peningkatan efektivitas kerja pegawai. Hasil penelitian menunjukan bahwa secara simultan, pengaruh Motivasi (X) terhadap Efektivitas Kerja Pegawai (Y) sebesar 70,3 %. Adapun pengaruh variabel lain (ε) terhadap efektivitas kerja (Y) sebesar 29,7 %, sedangkan secara parsial dari langkah-langkah Motivasi terhadap variabel efektivitas kerja pegawai dipengaruhi oleh besaran nilai langkah-langkah motivasi. Secara berurutan dari pengaruh terbesar hingga pengaruh yang terkecil dimulai dari sub variabel: Memberikan insentif yang terarah (X5)sebesar 24,40%, Memperhatikan kebutuhan rohani (X6) sebesar 19,30%, Menyertakan pegawai untuk diajak berunding (X7) sebesar 17,70%, Menciptakan suasan santai (X4) 12,30%, Memberikan gaji yang cukup (X1) sebesar sebesar 3,20%, Menempatkan karyawan pada posisi yang tepat (X3)sebesar 7,00%, dan Memberikan kesempatan untuk berkembang (X2) sebesar -7,20. Penelitian ini dapat disimpulkan bahwa Motivasi berpengaruh positif baik secara simultan maupun parsial terhadap efektivitas Kerja Pegawai di Kecamatan Lengkong Kota Bandung, dengan harapan efektivitas kerja pegawai dapat meningkat secara optimal

The Relation of Environmental Conditions With Charge Structure in Central Argentina Thunderstorms

In this study we explored the environmental conditions hypothesized to induce a dominant charge structure in thunderstorms in the province of Cordoba, Argentina, during the RELAMPAGO-CACTI (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations-Clouds, Aerosols, Complex Terrain Interactions) field campaigns. Hypothesized environmental conditions are thought to be related to small warm cloud residence time and warm rain growth suppression, which lead to high cloud liquid water contents in the mixed-phase zone, contributing to positive charging of graupel and anomalous charge structure storms. Data from radiosondes, a cloud condensation nuclei (CCN) ground-based instrument and reanalysis were used to characterize the proximity inflow air of storms with anomalous and normal charge structures. Consistent with the initial hypothesis, anomalous storms had small warm cloud depth caused by dry low-level humidity and low 0&deg;C height. Anomalous storms were associated with lower CCN concentrations than normal storms, an opposite result to the initial expectation. High CAPE is not an important condition for the development of anomalous storms in Argentina, as no clear pattern could be found among the different parameters calculated for updraft proxy that would be consistent with the initial hypothesis. &nbsp;</p

SUPPORTING SYSTEMS ENGINEERING ACTIVITIES BY ARTIFACT-ORIENTED DESCRIPTION AND SELECTION OF METHODS

Systems Engineering (SE) is becoming increasingly relevant in industrial application since more stakeholders are involved in engineering activities. To implement SE, companies have to adapt existing engineering processes and methods. This adaption requires knowledge about new methods as well as their integration into the engineering activities. In order to ensure goal-oriented identification of methods for different SE activities in this contribution an action field profile and the Systems Engineering Method Matrix are proposed. The development of both tools is driven by the assumption that most SE activities and methods can be described based on the artefacts the deliver. In order to get feedback about the proposed tools, semi-structured interviews with two industry partners were conducted, focussing on the tool\u27s usability. These interviews underline the basic usability of the tools and their support to identify SE activities to be supported by (new) methods. Moreover, requirements for further development and adaption are derived from the interviews

The Temporal and Probabilistic Relationship between Lightning Jump Occurrence and Radar-Derived Thunderstorm Intensification

No abstract availabl

Characterizing Lightning-Initiated Wildfire to Develop New Nowcasting Techniques for Wildfire Identification

No abstract availabl

Characterization of Optical Energy Output in Thunderstorms to Enhance Severe Thunderstorm Identification

No abstract availabl

Integrating Space-Borne Lightning Characteristics and Ground Based Metrics for Assessing Thunderstorm Intensity

No abstract availabl