First ground‐based measurements of OI 6300 Å daytime aurora over Boston in response to the 30 October 2003 geomagnetic storm

High spectral resolution measurements of OI 6300 Å emissions during daytime on 30 October 2003 from Boston revealed prolonged auroral activity from 1415–1900 LT. The solar zenith angles varied from 70°–115° during that interval. Intense enhancement in brightness of 38 Kilo Rayleighs were observed at 1509 LT, which were six times larger than the normal daytime emission rates for that day. During this event the solar zenith angle was 74° and the solar background continuum was 4 × 106 Rayleighs Å−1. Such large enhancement in brightness were due to the daytime aurora generated in response to an X‐class Coronal Mass Ejection on the Sun. The measured daytime airglow emissions show good agreement, both, in the magnitudes and in the temporal variability with the emissions modeled by using as inputs the Ne, Te and Ti profiles that were measured by the Millstone Hill Incoherent Scatter Radar (ISR) located approximately 60 km away from the spectrograph.