UNCERTAINTIES IN MEASUREMENTS OF ELECTRON-TEMPERATURE AND THE ESTIMATION OF F-REGION ELECTRON HEAT-CONDUCTION FROM EISCAT DATA

Heat conduction by electrons has an important influence on the tempera ture of the electron gas in the F2 region of the ionosphere. The rate at which the electron gas in a given volume is cooled by conduction is proportional to partial derivative(2)(T-e(7/2))partial derivative h(2 ). The electron temperature T-e can be measured as a function of heigh t h by incoherent scatter but the estimates of partial derivative(2)(T -e(7/2))partial derivative h(2) are highly sensitive to any errors in the measurements and to the fitting method used to calculate the secon d derivative. In this paper we derive a general formula for the random uncertainty in EISCAT temperature measurements using two independent methods and compare these with the errors quoted in the standard analy sis programme. The heat flux and rate of cooling are then estimated by fitting a polynomial curve to the height profile of T-e(7/2), using t he reduced -chi(2) parameter to determine the order of the fitted poly nomial justified by the accuracy of the data. The variation of heat Au x with height and Covington index (S-10.7) is discussed.