Stunning images of River Aire flow patterns taken by a Leeds amateur photographer have been fascinating people in New York.
Taken by retired Leeds University research fellow Ruth Robson, they were selected from entries submitted by photographers from across the world for an exhibition mounted by Art and Science Collaborations Inc (ASCI), an international organisation based in the US.
Her eye-catching prints are on display at the New York Hall of Science and have now been selected to feature in an online exhibition.
The photographs were taken from a footbridge close to a weir on the River Aire at Castleford.
The patterns are revealed by bubbles and highlighted by dissolved peat as the water flows over and around obstacles such as rocks and pylons.
In the images - called Fluvia Fluxum - the yellow-brown colour of the dissolved peat, has been enhanced to emphasise the flow patterns.
Ruth, who two years ago had an exhibition at West Yorkshire Playhouse, said: "I like taking photographs down by the River Aire and the Leeds-Liverpool Canal. I have taken pictures at different times of the year and day there and it's amazing how things change."
Ruth was born in America and came to England to study at Leeds University.
She returned to the USA but after a spell teaching came back to Leeds to do a doctorate.