A new scientific instrument
A new scientific instrument
The expedition’s first drifter has been launched.
The One Ocean voyage around the globe is a research expedition. Two students are running scientific instruments, taking samples, and doing observations. They stay on board a month or two each, working hard every day.
On this leg Nellie Wullenweber and Fabian Knoblauch are running the noisy lab down by the engine room. This week, a new assignment was added to their busy daily schedule: drifter dropping.
A drifter is a floating research device that is dropped into the ocean, and automatically transfers data to researchers on shore. The main purpose of the drifters is to report their positions, providing important information on the direction and speed of the ocean currents. The drifters send their position using a satellite uplink, and the researchers can follow their movements in real time.
The drifters also transfer the sea temperature and, some of them, barometric pressure.
The white and blue sphere at the right in the photo is the main part of the floater. The green fabric at the left will expand into a long tube, hanging below steadying the sphere.
Nellie and Fabian have been instructed to launch one drifter every 2 degrees longitude from 30 degrees west and all the way across the Atlantic ocean. The first drifter was launched October 12th. If the ship keeps up its current speed a drifter will be launched approximately every day, 13 in total.
The drifter experiment is administered by The Lagrangian Drifter Laboratory at UC San Diego, and is part of NOAA’s Global Drifter Program.
- They are excited that we are able to launch their drifters, I don’t think they get that opportunity every day, comments Nellie.
One of the co-sailors, Gro van der Mehren, has brought her own drifter, as a favor to one of her colleagues at the Institute of Marine Research.
From the 1940s up until the mid 60s, Institute of Marine Research made simple drifters. The system was old school: A glass bottle with a letter inside telling where and when the bottle was tossed into the ocean, and what to do if you found one.
The drifter that van der Mehren has brought onboard is one of these original drifters, but with a modern twist: a GPS tracker has been attached to the bottle, reporting its position back to her colleague at Institute of Marine Research.
Gro has been instructed to toss it into the water together with one of the student’s 13 drifters, in a week or so.
- It will be interesting to compare the data from the two drifters, the modern one and the veteran one, says van der Mehren excitedly, will they follow the same pattern?
The position of Gro’s drifter will be made available to anyone interested at the Institute of Marine Sciences web page.
The drifters will continue to report back for up to two years, before the batteries drain out. After that, they become ocean waste. This, of course, is a dilemma to the expedition as well as to the students onboard.
- It doesn’t feel good, but it would require way too much resources to collect them again. Hopefully, the benefits of the data from the drifters will outweigh the environmental cost, comments Nellie.