It's not a single study, though. There have been many studies showing the same results over the past 30 years.
Otherwise we are talking about feelings and hunches.
If Google Scholar is providing you with papers (other than this one, which is about rich Swedish people/Swedish people who go outside more) that prove your hypothesis (which you haven't even stated, just hinted at) then you should either link to those papers or not reply.
As for the discussion, there are multiple lines of evidence pointing to the fact that sunlight does in fact reduce mortality. First, this study controls for exercise, and also found that use of tanning beds reduces all cause mortality, so overall it's a pretty good study. We also know that vitamin D status is negatively correlated with mortality. We also know that nitric oxide reduces blood pressure, and is released from the skin by sunlight.