Using a new methodology,namely,Multiscale Window Transform(MWT),and the MWT-based multiscale energetics analysis,the cold center of the Atlantic blockings in the lower stratosphere is studied for an understanding of its generation mechanism. It is found that the generation is due to the canonical transfer of Available Potential Energy(APE) to the blocking scale window from both the processes shorter than 16 days and those longer than 64 days; the gained APE is then transported away northwestward and southeastward,and then converted into the blocking-scale Kinetic Energy(KE),causing the enhancement or persistence of the high-pressure centers.These processes are particularly conspicuous in the northwest,which could account for the northwestward extension of the blocking highs.Traditionally it is believed that,in the atmosphere,APE is transferred downward from large scale to smaller scales,but here we find that,when blockings occur,both the low-frequency and high-frequency processes transfer toward the blocking-scale window.Also,different from the previous finding that,in the troposphere the blocking-scale KE is converted into the APE on the same scale window to make the blocking decay,here in the lower stratosphere the conversion is in the opposite direction,i.e.,it is from APE to KE,making the blockings enhanced. Recent numerical experiments indicate that the dynamical processes around the tropopause are crucial for the development and maintenance of the blockings;this study will facilitate a deeper understanding of these processes.