Mapping the cloud-to-ground lightning occurrence in Fiji
نویسندگان
چکیده
Using the Time Of Group Arrival (TOGA) of sferics two year (Jan2003-Dec2004) annual average of about 3,200 and 1,200 cloud-to-ground (CG) flashes were recorded in the two larger islands, Viti Levu and Vanua Levu, Fiji. A two year average CG flash density showed maxima of 0.80 and 0.35 flashes/km per year in two islands. The diurnal variation showed peak activity between 14:00 hrs16:00 hrs LT and the seasonal variation showed enhanced lightning incidences during November-April. Data from Lightning Imaging Sensor (LIS) aboard the NASA Tropical Rainfall Measuring Mission (TRMM) satellite are also presented for the same period at the two locations. Lightning in a 10 km×10 km area was compared with total rain accumulation at a site midway in the area which shows good correlation.
منابع مشابه
Benefits of Very High Frequency Total Lightning Mapping over Very Low or Low Frequency Cloud Lightning Detection for Meteorological Applications
As a thunderstorm approaches a fixed asset (90% of the time) where people are located, VHF cloud lightning mapping provides 10s of minutes of lead time before the first cloud-to-ground strokes reach this asset. At times when a thunderstorm develops directly over the fixed asset (~10% of the time), the cloud flash detection efficiency exceeding 90% maximizes lead time during thunderstorm growth ...
متن کاملComparing high-speed video and Lightning Mapping Array observations to investigate the influence of ground strikes on lightning flash characteristics
This study presents exploratory observations for a set of 28 cloud-to-ground flashes recorded on highspeed video, each with a time resolution of 10,000 frames per second. The high time resolution, along with precise GPS timing, allows a detailed comparison of the videos with corresponding data from the Oklahoma Lightning Mapping Array (LMA). The LMA detects VHF radiation sources throughout the ...
متن کاملSome inferences on the role of lower positive charge region in facilitating different types of lightning
[1] It is generally thought that the lower positive charge region serves to enhance the electric field at the bottom of the main negative charge region and thereby facilitate the launching of a negatively-charged leader toward ground. On the other hand, the presence of excessive lower positive charge region may prevent the occurrence of negative cloud-to-ground discharges by ‘‘blocking’’ the pr...
متن کاملLightning morphology and impulse charge moment change of high peak current negative strokes
[1] We have analyzed very high frequency lightning mapping observations and remote magnetic field measurements to investigate connections between lightning morphology and impulse charge moment change (iCMC) of negative cloud-to-ground (CG) strokes with high estimated peak currents. Four lightning morphologies are identified for a total of 2126 strokes within optimum detection range of the North...
متن کاملOrigins of positive cloud-to-ground lightning flashes in the stratiform
7 [1] The origins of positive cloud-to-ground (+CG) 8 lightning in the stratiform region of a leading-line, 9 trailing-stratiform mesoscale convective system (MCS) are 10 investigated. Platforms include radars, NLDN data, and a 11 VHF 3-D lightning mapping system. This study examines a 12 small asymmetric MCS that occurred near the Colorado13 Kansas border in June 2000. In this storm 39 of the ...
متن کامل