Evaluating Sensitivities of the MSIS-86 Thermosphere Model.




Atmospheric models represent the state of the environment including interactions that occur in the atmosphere and are thus useful to predict future temperature and concentration densities of important species. A prominent example of an atmospheric model, in particular for the thermosphere, is the MSIS-86 model developed at NASA. In this note, we transform this computer program by means of the automatic differentiation tool ADIFOR to obtain a new computer program capable of evaluating the derivatives of the output of MSIS-86 with respect to its input. These sensitivities are quantified and compared with derivatives computed via numerical differentiation by divided differencing, demonstrating the reliability of automatic differentiation.