Dogs are simple experiential creatures. They react directly to the world around them and importantly input from us and they do this with no filter. If you notice they tend to react pretty much the same way to similar stimulus. Often the way we leave or say goodbye can stress a dog out which can cause barking.

Perhaps when you leave he now thinks he'll never see you again. Maybe maybe not. We'll never really know what is truly going on but the drama we ourselves create at every entry can directly impact how our dog perceives and then behaves.

If we treat every arrival and leaving with a huge fanfare, hugging, kissing, petting your dog is reading those signals and you are training him to expect that whenever you come and go. Do you want that?

If not you can deliberately tone down the attention you lavish on your pet at these times. Now this can be hard as who doesn't love their pet? This can be a challenge as for most of us it's hard to turn down unbridled affection from a loving dog especially at the end of a hard day. But remember your pet is not going away. Let me repeat. Your pet is not going away.

Some trainers say you shouldn't say goodbye, you simply pay no attention to the dog on leaving or returning. You don't say hello or goodbye you just go and return which will translate to your dog that coming and going is not a big event. That's quite a challenge for most so there is a balance point here.

You can make everything less dramatic by making it a lot more casual. No big hugging or petting session when you leave or arrive. A simple goodbye and hello. This clearly sets up that your arrivals and departures as no big deal and your dog will see them as such and not create a stir with barking or jumping.

Some times it good to see an excited dog when you return but it's important to make sure your dog doesn't use this as a pretext for barking, jumping on you and generally misbehaving.
Don't fall into the trap of giving your dog a 'treat' that lets him break normal house rules you'll only be starting something you'll have to fight later on.
Once the barking stops, wait a few seconds and keep eye contact, then praise him and pet him.