Photographed August 27th, 2019 looking towards the sunset, Hong Kong harbour. I'm not sure what the atmospheric cause would have been but am interested to hear any speculations!
The photo was taken by an iPhone 6 and is unprocessed. Happy to share the full size image if requested.
Looks like shadows cast by some objects (clouds near or below apparent horizon perhaps) on the regular forward-scattered sunlight.
Commonly termed, crepuscular rays.....