Low‐latitude thermospheric neutral winds determined from AE‐E measurements of the 6300‐Å nightglow at solar maximum

Abstract

Atmosphere Explorer E (AE‐E) measurements of the O(¹D) 6300‐Å emission in the nighttime equatorial thermosphere are used to infer the height of the F2 layer peak as a function of latitude and local time. The investigation is conducted both for northern hemisphere winter solstice and for spring equinox, under solar maximum conditions. The layer heights are used to derive magnetic meridional components of the transequatorial neutral wind, in conjunction with the MSIS‐86 model and previous Jicamarca incoherent scatter measurements of the zonal electric field. The AE‐E wind estimates indicate a predominant summer to winter flow for the winter solstice case. Comparisons are made with the empirical horizontal wind model HWM87 and with winds generated by the thermospheric general circulation model. The model predictions and experimental results are generally in good agreement, confirming the applicability of visible airglow data to studies of the global neutral wind pattern. Perhaps the most significant discrepancy occurs near midnight, where some of the data indicate a sharp decrease in the magnitude of the neutral wind. This feature, which has been observed in previous experimental studies, is not reproduced by either of the two models.