A warmer ocean affects the weather

Sailing from Palau to Yokohama, there were Japanese scientists on board, working at Jamstec, Japan Agency for Marine-Earth Science and Technology.

Satoru Yokoi is a meteorologist, and studies how the temperature of the sea affects the weather; how much it rains, and how intense the rainfalls are.

- The last few summers have been very hot in Japan, and Japan has received a lot of heavy rain. At the same time, we see that the sea surface temperature in the surrounding ocean is increasing faster than the global average, which may be the reason for this, says Yokoi.

Heated

The air above the sea surface is heated by the seawater, and brings water vapor with it as it rises. The warmer the sea, the more water evaporates, and the warmer the air above it is, the more water vapor the air can hold.

Yokoi and his colleagues brought three Argo buoys with them on their journey. With help from the crew, the buoys were launched along the way one by one. The buoys measure, among other things, the temperature and salinity of the seawater.

- We want better and more frequent measurements of the temperature and salinity in the sea, says Yokoi, and continues.

- The salt can be seen as a tracer that tells us where the seawater comes from, and how seawater from different places physically mixes, and also how much it rains. Rainwater reduces salinity.

Argo

There are currently 3,926 such Argo buoys floating around the world's oceans. Measuring instruments and communication equipment are mounted on top of yellow 1,5 meter long pipes. Inside the buoys is an air-filled bladder, and a motor that can fill up or contract it.

This makes the buoy capable of moving up and down in the sea. When the buoys are launched, they sink to predefined depths, where they drift around for ten days recording the conditions in the water around them. Then they ascend, and send the information home via satellite.

How the buoy has moved reflects the strength of the ocean currents in the area.

- It is a point for us to contribute to this international network, which monitors the ocean all over the world. We hope the buoys will work for a couple of years, and give us data that can be used in our studies of how the ocean and the atmosphere affect each other, says Yokoi.

Better than a bed

Yokoi has not only been researching his way across the ocean, he has done watch-duty like the rest.

- I like it very much, especially being up in the rigging. I was really scared, but once I tried I found that going up was not so scary, and I could enjoy the very beautiful scenery from the upper part of the ship. I also enjoyed the hammock. This is my first time sleeping in a hammock, and I think it is better than sleeping in a bed, he smiles.

But behind all the nice experiences lies the seriousness of the One Ocean Expedition.

- All people who live close to the coast should know that we should take care of the sea. We know that fisheries are a major source of microplastics, and we must also reduce the amount of garbage, says Yokoi.

- There are a lot of young people on board, from different countries, working hard sailing the ship together. This is very important for the future, to work together internationally to solve global problems.