Mapping Lightning Strikes in KSA “Using numerical methods as a tool” Tamer Al-Alami996423

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  • Slide 1
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  • Mapping Lightning Strikes in KSA Using numerical methods as a tool Tamer Al-Alami996423
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  • Verses from Quran ( . 0 __________________________________________ ( )
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  • Lightning Definition Abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission of light Flash of light that accompanies an electric discharge in the atmosphere which can scintillate for a second or more
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  • Facts A lightning bolt can carry 30,000 A at several hundred million V. In the average year, lightning strikes the US about 20 million times. Florida is easily the national lightning Mecca Even a modest storm cloud can generate the energy of a small nuclear power plant (a few hundred MW) Temperature of lightning's return stroke can reach 50,000 deg F, hotter than the surface of the sun is ~ 11,000 F)
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  • Lightning Clip
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  • Stroke mechanism
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  • Advantages of Lightning 1.Research indicated that it may be a very good indicator of the strength of convective storm systems 2.Timely hazardous weather & tornado warnings 3.Improved forest fire & wild-land fire management
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  • Disadvantages Fires (lighting bolt, heating effect) Injury Damage Destruction
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  • Examples of Disadvantages Telecommunications firm shut down Burn chemical plant Millions of dollars of petrochemical products & facilities are destroyed each year by lightning-related phenomena in many parts of the world while lives are lost when these facilities are ignited or explode
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  • Mathematical equations Td = # of thunderstorm days / yr or keraunic level The Avg ground flash density may be estimated using:
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  • Mapping It is helpful to construct a visual representation of lightning strike densities in countries such as Saudi Arabia in order to locate areas which are most likely to be stroked & those which are not
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  • Lightning map
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  • Lighting map
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  • Lightning map of Saudi Arabia
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  • Importance of Map Comparing the lightning map to locations of Transmission lines illustrates importance
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  • Animation for Lightning Map
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  • Mapping example
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  • Early Mapping Example
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  • Lightning Detection Systems Lightning Imaging Sensor (LIS) Optical Transient Detector (OTD) Lightning Mapper Sensor (LMS) Lightning Detection and Radar (LDAR) Aviation detection
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  • Lighting imaging sensor (LIS) The LIS is a science instrument aboard the TRMM Observatory, which was launched on 28 November 1997 from the Tanegashima Space Center in Japan
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  • Lighting imaging sensor (LIS) has a staring imager optimized to locate & detect lightning with storm-scale resolution (4 to 7 km) over a large region (600 x 600 km) of Earth's surface. TRMM Satellite travels a distance of 7 km / sec as it orbits Earth, allowing LIS to observe a point on Earth or a cloud for ~ 90 sec as it passes overhead, long enough to estimate flashing rate of most storms
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  • Lighting imaging sensor (LIS) Enables detection of distribution & variability of total lightning: Cloud-to-cloud Intra-cloud Cloud-to-ground
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  • Lighting imaging sensor (LIS) The instrument records: 1.Time of occurrence 2.Measures the radiant energy 3.Determines the location of lightning events within its field-of-view
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  • Lighting imaging sensor (LIS) Data from this sensor is used to study mesoscale phenomena such as: Storm convection Dynamics Microphysics
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  • Lighting imaging sensor (LIS) A Real Time Event Processor (RTEP), inside the electronics unit, used to determine when a lightning flash occurs, even in presence of bright sunlit clouds 90% detection efficiency
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  • LIS This is the latest lightning map obtained using OTD Nov 31, 2003 Based on: data sheets
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  • Optical Transient Detector (OTD) Highly compact combination of optical & electronic elements developed by NASA capable of detecting the momentary changes in an optical scene which indicate the occurrence of lightning
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  • OTD OTD was launched on April 3, 1995 aboard the MicroLab-1 satellite into a near polar orbit at an inclination of 70 deg with respect to the equator
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  • Optical Transient Detector (OTD) Advantages: 1.Gather lightning data under daytime conditions as well as at night 2.Provides much higher detection efficiency & spatial resolution than has been attained by earlier lightning sensors
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  • OTD The OTD detects lightning flashes during both day & nighttime conditions with a detection efficiency ranging 40% - 65%, depending on external conditions such as glint & radiation Unsuitable for studying localized weather
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  • Optical Transient Detector (OTD) 100-deg field of view, it surveys virtually all areas of the globe where lightning normally occurs
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  • OTD "Flashes" are determined by comparing the luminance of adjoining frames of OTD optical data.
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  • OTD continue If the difference is more than a specified threshold value, an "event" is recorded. One or more adjacent events in the same 2ms time frame is recorded as a "group". One or more groups within a sufficiently small time period are classified as a "flash". These are grouped into "areas" if there are one or more sufficiently separated from existing areas
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  • Contributions of OTD Discovery of potential lightning indicators for application to more timely hazardous weather & tornado warnings Use of lightning as a proxy for detecting intense atmospheric convection Production of the most complete & detailed maps of the global lightning distribution Discovery that the global flash rate is approx 40 flashes / sec < of the widely accepted estimates dating back to 1925
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  • Lightning Mapper sensor (LMS) Sensor, capable of continuously mapping lightning discharges during both day & night, with a spatial resolution of 10 km, in geostationary orbit. It is capable of detecting & locating both cloud-to- ground & intra-cloud discharges with high spatial resolution & detection efficiency, (storm-scale resolution) over large areas of the Earth's surface
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  • Lightning Mapper sensor (LMS) A Lightning Mapper Sensor would be capable of detecting all types of lightning phenomena, and will provide near uniform spatial coverage
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  • Lighting Detection & Ranging (LDAR) Network of lightning-monitoring stations at Kennedy Space Center used for measuring & indicating 3D locations & times of lightning flashes that have occurred within distances up to 10s of kms
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  • Lighting Detection & Ranging (LDAR) The position from which a signal originated (presumed location of lightning flash) can be computed from the speed of light, the differences among the times of arrival of the signals, and known positions of stations
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  • Advantages of LDAR Sensitivity it detects & locates essentially all lightning, including inter- & intra-cloud strokes Detects earlier than other systems more comprehensive info on the evolving 3D distribution of lightning activity in the vicinity
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  • Continue Advantages A typical commercial system locates 1 pt / flash or return stroke, whereas for one flash, the LDAR system locates an avg = 200 pts, covering an average ground A = 11.4 km 2. Commercial lightning-monitoring systems generally provide only 2D location data with errors = 2 km, whereas the LDAR provides radar- like 3D location data with errors = 150 m.
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  • LDAR system
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  • Continue Trend toward micro-miniaturization in electronic systems development brings an increasing sensitivity to transient phenomena. Transients of < 3 V peak or energy levels as low as 10-7 J can damage or confuse these systems & their components.
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  • Lightning Probability One of the main driver's of lightning activity is temperature. The closer to the equator, the more risk of experiencing lightning Proximity - the closer to the storm cell (cloud), the greater the field intensity & risk Degree of exposure the closer it sticks out with little cover from surroundings, the greater the risk for a strike
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  • Aviation detection Rocket-triggered lightning
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  • Aviation detection Provide detailed info of the discharge's characteristics provide in-cloud measurements of thunderstorms Replaces optical measurements of in-cloud lightning which are severely affected by light