Must I have the ASCA application running if I'm using the Global Automatic feature, or can it be closed and can I just have AS16 running?

Thanks.

From the ASCA manual :

Global Automatic Theme (Requires AS16)
This dynamic theme includes automatic weather influenced support for all content categories. When activated, ASCA and AS16/ASP4 will constantly communicate with each other and load new content on-the-fly when weather changes dictate. When a change occurs, the new content will appear at various intervals slowly to prevent instant transitions as much as possible. This theme is called “Global” because the cloud textures applied over the cloud structures will be duplicated throughout the entire scene, similar to the default simulator and/or traditional graphics add-ons. The textures will change periodically through the flight, but when they change, it affects the entire scene.