The longitudinal variation of night airglow intensity in the region of the South Atlantic magnetic anomaly

Shipboard measurements made in the regions of the South Atlantic anomaly at a geomagnetic latitude corresponding to L = 1.80 suggest the existence of a region of increased airglow activity near 67° geomagnetic longitude. We attempt to show that this anomaly is not temporal in nature nor due to the effects of high-altitude nuclear tests carried out during these measurements. The location of this anomaly borders on but does not pass through the magnetic and trapped particle anomalies as previously measured, and, although the results suggest that this anomaly is dependent on longitude, the quantity of data is limited and confirmatory measurements will be required to substantiate this conclusion.