I do not find him as an emigrant from Bergen, and also looked at Oslo. Is it possible that he was a sailor like his younger half brother is listed as on the 1900 census? Did he 'jump ship' or arrange his passage to work his way across? In that way, they are not usually listed on the emigrant registers.
I goofed on my earlier posting - the other daughter Helene - the twin, is not with them in 1900. Not sure if she died.
There are two more things to search. There is a bygdebok for Lindås - a farm and family history book. I will look for a lookups volunteer who might have that information.
Also, there is sometimes a register in a parish of those who asked permission to leave the parish. Mikael might be on that.