Emission heights of narrow bipolar events in a tropical storm over the Malacca Strait

• Published in: 2017 International Conference On Electrical Engineering And Computer Science (Icecos) pp. 305 - 309
• Main Authors: Ahmad, Mohd Riduan, Periannan, Dinesh, Sabri, Muhammad Haziq Mohammad, Zoinol Abidin Abd Aziz, Mohamad, Gaopeng Lu, Hongbo Zhang, Esa, Mona Riza Mohd, Cooray, Vernon
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.08.2017
• Subjects: Computer science; Electrical engineering; Emission height; Lightning; narrow bipolar event; Niobium; Radar; Reflectivity; Storms; tropic
• ISBN: 9781479976751; 147997675X; 9781479976768; 1479976768; 1479976741; 9781479976744
• DOI: 10.1109/ICECOS.2017.8167155

Emission heights for narrow bipolar events (NBEs) have been reported mostly from observations at mid latitudes but none have been reported from tropical regions. In this paper, we are reporting for the first time the heights of NBE emissions from a tropical storm over the Malacca Strait, a narrow water passage between the Malay Peninsula and Sumatra Island. A total of 49 positive NBEs (+NBEs) were detected from the storm. The NBE activity can be divided into two stages according to the emission heights and radar reflectivity data. The first stage (or S1) lasted for only 6 minutes, started with the first detected NBE, and produced 20 NBEs (41%). The emission heights ranged between 12.0 and 16.7 km. Radar reflectivity data showed that the storm reached maximum values at 55 dBZ within the period S1. In contrast, the second stage (S2) lasted longer (32 minutes) and produced 29 NBEs (59%). The emission heights were lower and ranged from 8.5 to 13.7 km. Radar reflectivity data showed that the storm reached maximum values at 50 dBZ within the period S2.