Thermal structure of the equatorialE-region over Thumba

Photoionization and absorbed energy rates have been computed by making use of the latest available semi-empirical solar XUV fluxes and cross-sections for two rocket flights for electron density measurements on 3 March, 1973 and 7 April, 1972 corresponding to low and medium solar active conditions over Thumba. Various heating and cooling rate profiles have been computed by making use of the latest available information. Various efficiency parameters such as photoelectron heating efficiency, photoionization efficiency, and ultraviolet heating efficiency, that are extremely important in understanding the thermal structure of the ionosphere, are clearly defined and distinguished.