The 46-year-old Jewell will be among the spectators for Wednesday's Carling Cup semi-final with Arsenal before beginning his attempt to rebuild confidence at Portman Road.
Jewell said: "Tony (Loughlan) and Charlie [McParland] will be in charge on Wednesday night and I will take charge on Thursday. I've not even met the players or the staff yet, it's been a real whirlwind and I don't want to cause a distraction. I have DVDs to watch this afternoon and I will be in the stands on Wednesday night."
Jewel’s long term goal is getting the Tractor Boys back into the top flight.
"I've had a few opportunities to come back in but this one ticked all the boxes and I can't wait to get started," he said. "I'm not here to say Roy Keane failed here. It's always sad when a manager loses his job but I am going to do my best.
"I have great respect for Roy as a player, a manager and a man but for whatever reason it hasn't worked out here. I have what it takes to get sides promoted. There are no guarantees but I can promise that there will be no stone unturned in guiding this club to promotion which is the long-term target.
"Confidence is at a low ebb but hopefully we can consolidate. There is no quick fix. I don't want to be negative but you normally need about 74 points to get in the play-offs which would mean we need another 46. That is a big ask. As long as we can see progress and consolidate that is the immediate aim."