Ron Smith of Yale continues his course The Atmosphere, the Ocean and Environmental Change with a lecture on how Earth's seasonal cycle reshapes global weather patterns. He explains the shifting bands of precipitation between hemispheres, the movement of the polar front between mid and high latitudes that drives frontal cyclones, and the seasonal migration of the Intertropical Convergence Zone across the equator. From there he covers how regional climates are classified using temperature and precipitation data, tying the classification scheme back to areas affected by ITCZ and polar front shifts. The lecture moves through chapters on Arctic sunlight seasonality, zone shifts, precipitation patterns, classification systems, and concrete regional examples, closing with a look at seasonally controlled weather events. Recorded in Fall 2011 as part of Yale's open course GG 140.