I think it's lens flare, caused by the backlight in combination with the lens (or lens-sensor interaction). It's not color noise (that's random speckled color pixels in low light/high iso images)
The way to deal with it is selectively select the area (with some feather) in photoshop and on a separate layer selectively adjust, color, contrast, clarity, brightness etc. until it looks the same as the piece of rock to the left and below. I've had mixed success with trying this, it takes quite some time with lots of trial and error, so only worthwhile for a few pictures that are really worth the significant time investment.