GoPro or How to quantify white caps at the surface of the ocean ?
Several groups of NAAMES are interested in the surface of the ocean covered with white caps.
Why do we care about white caps? White caps have an important role in the air sea exchange, they are a mix of air and sea water that form when a wave break. When bubbles break at the surface they carry out of the water particles (made of viruses, micro-organisms, organic molecules and salts) which when the bubble burst get into the air and become marine aerosols, that influence cloud formation and even hurricane dynamics.
A few models exist mainly based on wind speed and/or wave height but how could we validate them? No one was taking direct measurement on the previous NAAMES campaign. We decided to get cameras to do it, but had only 2 days before leaving dock. We scurried to Best Buy to get GoPros and are now taking pictures of the ocean every 5s, with one camera at each side of the boat. We deployed the cameras in front of the bridge, one of the highest point on board, known for its nice view on the ocean. The only issue with those little cameras is their battery; they last only 2 hours of continuous operation. A little waterproof case was built with the on-board supplies (tape and zip-ties) to protect the wire connection from water. The cameras are continuously running during the day and allow us, with a little bit of image processing, to retrieve the relative amount of white caps at the surface of the ocean.
We collect a little more than 12000 pictures/day and will be happy to share them with anyone having a fun project for them!
Written by Nils Haëntjens and Emmanuel Boss
Tags: NAAMES-III 2017