Applying Vondrák narrow-band filters on high precision Length of Day (LOD) measurements provided by space observation techniques as well as Atmosphere Angular Momentum (AAM) computed by U.S. National Meteorological Center (NMC), we show variation in amplitude of the annual components. From filter series of LOD and AAM, we find that annual variation of the LOD induced by AAM is about 20% higher than observed one. The aim of this work is to investigate how far the torque applied by the solar wind on the Earth's magnetosphere could contribute to explain this excess. The advocated dynamical mechanism could counterbalance annual discrepancies between AAM and LOD by an amount of 20%. Therefore, the torque produced by the solar wind on the earth might be considered as one of the most possible contributions to annual fluctuation in LOD.