At first I thought these pictures were Photoshopped. (Anyway, that's what my mind screamed)
Looking all to much like the Flying Spagetti Monster, a bit of research showed the images to be genuine and accurate, and I even uncovered a video (see link) of the joint US and South Korean military execise. The smoke rings/donuts are from smoke shells fired as part of the practice. Retouching may have gone a bit far on the 1st image. Photos from across the net, no copyright infringement intended. Happy to credit where it's due.
This looks only a wee bit fake. Sunlight lighting up the images, or Photoshop running riot?
Most likely due to over-saturation with yellow and sharpening of the images
More lifelike images from the opposite side