Several nights of optical and radar data were obtained from February 3 to 10, 1986 at Sondre Stromfjord, Greenland during a great geomagentic storm when Ap reached 202. These data, excluding O I (630.0 nm), were used to monitor changes in O and O2 densities in the region from 100 to 200 km and are consistent with results of Hecht et al. (1989) wherein the O I (630.0 nm) emission was used. That is, there were large depletions of O in the E region during the peak of the storm. Using 24-hour Ap values both MSIS-83 and MSIS-86 underestimated the depletion of O during the storm. MSIS-86 did noticeably worse than did MSIS-83, probably a result of the low exospheric temperature predicted by MSIS-86. However, when 3-hour ap values were used both models did better in predicting the measured O depletions, although MSIS-86 again was less successful than was MSIS-83. The data results also show that the enhancements in O2 were less than predicted by MSIS models in either mode. From 0200--0230 UT on February 9, 1986, a time just after the peak of geomagnetic activity as measured by Kp, the O mixing ratio near 135 km was found to increase by nearly a factor of 2. This increase is consistent with the passage of an atmospheric gravity wave through this altitude region providing that the scale height of O above 140 km is greater than predicted by the model. ¿American Geophysical Union 1991