The upward plasma drift and equatorial ionization anomaly (EIA) in the Earth's ionosphere are strongly influenced by the zonal electric field, which is generated by the wind dynamo. Specification and forecasting of thermospheric winds thus plays an important role in ionospheric weather prediction. In this study, we assess the impact of assimilating thermospheric wind observations from the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument on NASA's Ionospheric CONnection (ICON) explorer satellite on the ionospheric electrodynamics. Empirical Localization Functions (ELFs) of ICON/MIGHTI zonal and meridional winds are also computed and applied to our data assimilation experiments, enabling improved assimilation of the ICON/MIGHTI wind observations. Three Observing System Simulation Experiments (OSSEs) are performed using the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (WACCMX) with data assimilation provided by the Data Assimilation Research Testbed (DART) ensemble adjustment Kalman filter. OSSEs with and without assimilating synthetic ICON/MIGHTI zonal and meridional winds are performed from 0000 UT of 02 December to 0000 UT of 31 December. These two OSSEs are referred to as OSSE-MIGHTI-GC and OSSE-GC, respectively. The localization function for these two OSSEs is the Gaspari-Cohn function. In addition, an OSSE with ELF is performed using the same settings and same set of observing systems as OSSE-MIGHTI-GC. This OSSE is referred to as OSSE-MIGHTI-ELF. This project contents thermospheric data (zonal and meridional winds) of OSSE-MIGHTI-ELF. The rest data can be found in: - The ionospheric data (plasma drift and electron density) of OSSE-MIGHTI-GC can be found in project: WACCMX+DART ICON MIGHTI DA - Ionosphere -1, doi:10.17605/OSF.IO/3W8DY - The thermospheric data (zonal and meridional winds) of OSSE-MIGHTI-GC can be found in project: The impact of ICON/MIGHTI zonal and meridional winds on upper atmosphere weather specification in a whole atmosphere data assimilation system - 1, doi:10.17605/OSF.IO/DM5HJ. - The ionospheric data of OSSE-GC can be found in project: WACCMX+DART ICON MIGHTI DA - Ionosphere -2, doi:10.17605/OSF.IO/FK5PB - The thermospheric data of OSSE-GC can be found in project: The impact of ICON/MIGHTI zonal and meridional winds on upper atmosphere weather specification in a whole atmosphere data assimilation system -2, doi:10.17605/OSF.IO/6ADRE. - The ionospheric data of and OSSE-MIGHTI-ELF can be found in project: WACCMX+DART ICON MIGHTI DA - Ionosphere -3, doi: 10.17605/OSF.IO/TC79G