CrowdScience listener Eleanor was lying in bed one rainy evening, listening to the radio. She lives in New Zealand, but happened to hear a weather forecast that told her it was raining in the UK too. She started wondering: could it be the same rain falling there and outside her window in New Zealand? Can a raindrop really travel all the way around the world? There are a number of routes the droplet could take, including traveling as moisture in the air. Presenter Caroline Steel meets meteorologist Kei Yoshimura, who puts his powerful weather simulation to work plotting the raindrop’s journey through the sky. What if the raindrop falls along the way and gets trapped? Where might it end up? Hydrologist Marc Bierkens talks Caroline through the detours it could take, ranging from short stop-offs in plant stems to extremely long delays in deep groundwater. Finally, could the drop of water make it to New Zealand by circulating through the world’s ocean currents? Oceanographer Kathy Gunn maps the droplet’s path through the ocean – and explains how climate change might affect its journey. Featuring: Prof. Kei Yoshimura, Professor of Isotope Meteorology, University of Tokyo Prof. Marc Bierkens, Professor of Earth Surface Hydrology at Utrecht University Dr. Kathy Gunn, Lecturer in Climate Sciences at the University of Southampton Presenter: Caroline Steel Producer: Phil Sansom Editor: Cathy Edwards Production Co-ordinator: Liz Tuohy Studio Manager: Tim Heffer Additional recording: Knut Heinatz (Photo: Textures of rain on the surface of the ocean. Credit: Philip Thurston/Getty Images)
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I'd listen to the Today program when I'm falling asleep at night.
And so I just had it on while I was lying, going to sleep, and it's had the weather forecast and it said that it was raining.
Meet Eleanor.
She listens to radio from the UK but lives in New Zealand.
And then I was listening out my window and I could hear it was also raining.
I thought, oh, yeah, it's raining.
I went, no, wait a second, it's raining really, really far away in London and it's raining in Auckland.
I thought, wait a second, do those raindrops, how long do they actually come over to New Zealand?
Do they travel the world or do we just have like the rain from our local area?
I just wondered if there is there a movement from all the way up in London to all the way down in Auckland or not, and if there is, how long it will take.
This is CrowdScience from the BBC World Service.
I'm Caroline Steele and I love questions like this.
So does Eleanor.
She's a science teacher, so she's used to answering all sorts of weird and wonderful questions from her students.
But this time, thanks to the rain outside her window, it's her turn.
I was wondering how long a water droplet from London would take to travel all the way to New Zealand and drop his rain here.