Looks like it could be replicated with a curves gradient mask and upping the shadows/midtones/highlights individually to taste. Then add a touch of color on the same gradient mask to mimic the warm tones of the sun flare.
Or try painting on a new layer set to Screen blending mode. Start out painting in maybe ten to fifteen percent opacity brush strokes and build it up to suit. It's a technique I've used many many times over the years.