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Abstract Measuring the temperature of lightning is a fundamental part of understanding the evolution of the plasma channel, and it is also crucial to quantify its chemical and energetic impacts in the atmosphere. Nonetheless, due to complications that have both to do with the complexity of the source and required equipment, this has only been done in a few studies to date. Here we report on the design and implementation of an instrument to perform simultaneous, multi‐band optical and radio observations of lightning, which aims to provide a fast and simple way to routinely measure its temperature. The primary instrument includes photometers to measure temperature and electric field sensors to identify lightning sub‐processes. Data are analyzed in tandem with 2D and 3D lightning location information. To measure the temperature, the photometer array includes 3 channels equipped with narrowband filters (1 nm) centered at bright atomic oxygen lines in the near‐infrared, and temperature is given from the relative intensity of optical emissions across the 3 channels. We found the average peak temperature of 44 negative cloud‐to‐ground lightning return strokes to be 17,600 K. Additionally, the peak temperature had no apparent correlation to the peak current. Comparisons between 777 nm observations from the ground and from space by the Geostationary Lightning Mapper (GLM) emphasize the picture that the instruments in these two vantage points tend to see different portions of the lightning flash. They also reveal that dart leaders play a key role in the interpretation of lightning observations from space. 

Abstract This study describes results from video observations of five intracloud flashes located ≤ 20 km from the camera and recorded with 6.1 µs exposure time and 6.66 µs frame intervals. Video data are supported with electric field change (E-change) and VHF measurements, with emphasis on the flash initiating event (IE) and initial breakdown (IB) stage. In four of the five flashes, the IE is accompanied by weak luminosity, ≤ 5% above background, lasting for 300–500 µs. Two of these four IEs were positive Narrow Bipolar Events (NBEs) with VHF powers of 43 and 990 W; these are the first (known) data showing visible light detected with a positive NBE. Two other IEs with weak luminosity had powers of 0.5 and 1 W, and the IE with no detected luminosity had a VHF power of 3 W. A typical IB cluster consists of several narrow pulses and one classic pulse in E-change data (along with many VHF pulses), and each example flash has 2–10 IB clusters in the first 5–50 ms. The luminosity of IB clusters was substantially greater than IE luminosity, ranging from 10 to 40% above background in four examples, while for one flash with 10 IB clusters, the luminosity range was 35–360% above background (average 190%). Luminosity durations of IB clusters were 520–1750 µs with average 1210 µs. For both IEs and IB clusters, increases in the detected luminosity were closely timed with substantial VHF emissions and decreased when VHF emissions weakened.