I way wondering if you could outline the accepted minhag of when to close the Aron Hakodesh on shabbos morning and indeed every time we open it?
Should it be closed after Brich Shemai when the chazan has been given the torah or should it be left open until the chazan has recited the line of Gaddelu?
It can be closed after everyone says Brich Shemai. The idea of keeping it open is because when we take out the sefer torah it is an es tzon and special time to daven, and this is the reason we say Brich Shemai, however after that it can be closed.
Pisefer torahskei Teshuvos 134-12