NO2 continuum in aurora

The chemiluminescent association of O and NO to form NO2 gives a continuum emission. A continuum is known to be present in the auroral zone. The results of a number of measurements of this continuum emission are reported. They were made by rocket-borne instrumentation which penetrated auroral forms of various intensities. The NO densities are of the order of 1000 to 4000 million per cu cm at 110 km. This represents an enhancement at this altitude by over an order of magnitude from mid-latitudes.