No abstract

The excitation energy of O(¹D) is a potentially significant heating source in the region 60–150 km. Some of the O(¹D) energy is thermalized directly by collisional deactivation, some of it is radiated at 6300 and 7619Å and thus lost to the atmosphere, and the rest of the O(¹D) energy (about 25%) enters the near‐resonant N2(υ = 1) −CO2(001) system. Since the atmosphere is optically thick to 4.26‐μm radiation below about 80 km, the O(¹D) energy that enters this N2‐CO2 system and is not locally quenched is multiply scattered to other altitudes where it can be thermalized or lost out of the top of the atmosphere. Our calculations show the relative proportions of each of the O(¹D) energy loss options.

Sporadic‐E (ES) data from Japan were presented to show the temporal variations in sporadic‐E blanketing frequency (ƒbES), virtual height (h′ES), and frequency of occurrence. Tidal winds were substituted into the wind‐shear theory of ES to calculate electron density profiles and determine the influence of the tidal winds in the asymmetry of the ES occurrence variation. Results showed that the tidal wind model used was not strong enough to significantly influence the formation of molecular ion ES layers, but that the winds did have the proper orientation to accumulate and layer metallic ions in the late afternoon. The role of metallic ions in afternoon ES will have to be established.

The midlatitude nighttime E region was modeled with three ion species including a metallic ion species, Mg+. Time‐dependent ionization profiles, including diffusion, were calculated for five wind profiles measured over Wallops Island, Virginia, on 22 February 1968. Model‐generated profiles are compared with electron density measurements from the same night.

No abstract