Atmospheric rivers (ARs) can induce significant melting of sea ice as they approach the ice cover. However, due to the complex physical properties of sea ice, the specific processes within the ice pack that are responsible for its response to ARs remain poorly understood. This study aims to shed light on this question using a stand-alone sea ice model forced by observed atmospheric boundary conditions. The findings reveal that the ARs induced ice melt and hindered ice growth in the marginal seas can be attributed to a combination of thermodynamic and dynamic processes. The AR-wind transports ice floes from the marginal seas back to the central Arctic dynamically, resulting in a thickening of the ice cover in that region. Among the thermodynamic processes, reduced congelation growth (54-56%), enhanced basal melting (17-26%), and inhibited snow-ice formation (11-21%) play major roles in the sea ice loss in the marginal seas.