SePohl is not a Latvian name. Latvian names do not have prefixes or extra capitalization in the style of Scottish/Irish or French names (MacDonald, LeBlanc, etc.). It could be a corruption of the name "S?pols", which is a Latvian name that means "onion".
Lebar is also not a place I've ever heard of, or can find any record of. Do you mean Libau, the old name for Liepaja? Liepaja is a Latvian port city that many people left from when emigrating.
What ethnicity was your ancestor? What was his religion? Any family members? When was he born? All of this information will help track him down.