There is a compelling need for intensive study of convective impacts on the summer stratosphere over North America. Each summer the North American Monsoon Anticyclone (NAMA) dominates the circulation of the North-Western Hemisphere and acts to partially confine and isolate air from the surrounding atmosphere. Strong convective storms in the NAMA regularly penetrate deep into the lower stratosphere (LS), with some ascending above 20 km (~450 K potential temperature). The uniqueness of the NAMA region is most easily seen in satellite measurements of water vapor, which show a large enhancement in the LS over North America not seen either in magnitude or at such high latitudes elsewhere around the globe. But the coupling of tropopause-penetrating convection with large-scale monsoonal motion is poorly understood, as is the impact of convection on the chemical composition of the LS, both in monsoon regions and in the global stratosphere, which receives inputs of moist and polluted monsoon air from the NAMA. The Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) project directly addresses this knowledge gap.