Effects of Forcing Uncertainties on the Thermospheric and Ionospheric States during 2013 St. Patrick's Storm

Upper atmospheric weather prediction is subject to various types of uncertainties of energy sources. Understanding the sensitivity of the thermosphere and ionosphere to the uncertainties of energy sources under different geomagnetic conditions is critical for space weather prediction. This paper aims to perform the ensemble simulation of a whole atmospheric model with various kinds of forcing perturbation to evaluate the upper atmosphere's response to the uncertainties of different energy sources.

Two kinds of forcing uncertainties are addressed: the uncertainties of the lower atmospheric wave and tides and uncertainty of the high-latitude electric potential. Uncertainties of these forcings are estimated via different procedures and are applied to generate forcing perturbations. The NCAR's Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM-X) is applied in the ensemble simulation experiments. With the help of WACCM-X, we can simulate the propagation process of the lower atmospheric forcings and the response of thermospheric and ionospheric states to the uncertainties of the lower atmospheric forcings. The uncertainty of high-latitude electric potential is estimated based on the SuperMag and SuperDARN data through CU Boulder's Assimilative Mapping of Geospace Observations. It is used to generate the forcing perturbation of high-latitude electric potential in the WACCM-X.