Lately I am noticing the subtleties of a summer sunrise. I mean not even I can rise early enough in June and July to walk before the sun is fully risen, no matter what advantage that would give me in terms of temperature and crowded sidewalks.  In the heat of the past month here in DC, the word subtleties would not have seemed to apply to the way I experienced the sun on my morning race to get my exercise in while being outside was still mildly possible. But as August moves into September, more and more days, my feet step out onto the pavement with light, yes, but with…