Abstract
Lightning spectra in the 850‐ to 1400‐nm near‐infrared region have been recorded with 200‐ to 300‐ms time resolution using a slitless spectrometer with a lead sulfide detector. Except for the wire portion of triggered discharge channels, rocket triggered and natural return stroke spectra are very similar. The following neutral atomic nitrogen (NI) and oxygen (OI) multiplet emissions have been identified (the wavelength, in nanometers, of the brightest line in each group is shown in parentheses): NI(2) (821.6), OI(4) (844.6), NI(1) (868.0), NI(15) (906.1), OI(8) (926.6), NI(7) (939.3), NI(19) (986.2), NI(18) (1011.3), NI(28) (1053.9), and NI(36) (1246.8). Continuum emissions with peak intensities at least an order of magnitude less than the strongest line emissions were detected. A laboratory arc simulation of a return stroke discharge produced a near‐IR spectrum containing all the features emitted by lightning. Additional NI radiation peaks at 1131.4 nm (NI(17)) and 1358.1 nm on the arc spectra overlapped water vapor absorption bands and were not visible on lightning spectra recorded at 2.2‐km range. A time‐averaged lightning channel temperature of about 16,000°K was calculated from the ratio of relative intensities of the NI(1) and NI(18) multiplets.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.