August 15, 2017

A Simple Design for a Complex Purpose: MIT Sea Grant summer UROP Rachel O’Grady

By Bayley Connors, BURECS

Drifters, often no more than three feet long, are incredibly simple in design. This does not understate their utility, marine scientists have used them for decades to map the currents of world oceans. Rachel O’Grady, a UROP student with MIT Sea Grant, will be expanding the capacity of a self-made drifter.

O’Grady spent her summer as an intern with Dr. Thomas Consi, MIT Sea Grant’s Research Education Specialist. She added three sensors to the drifter’s design to measure salinity, pH, and temperature. These sensors are found alongside an onboard GPS, allowing O’Grady and researchers alike to know the precise location of each data point.

The plan is to deploy the drifter at the mouth of a river, where it will collect data on the effects of river discharge river on coastal acidification. River water is generally more acidic than ocean water, thus decreasing the pH of areas where rivers flow. For now, O’Grady focused her drifter’s utility on the Boston Harbor and Charles River.

While O’Grady was only able to deploy her drifter once this summer, she views her project as long-term. “The endpoint,” she says, “will be looking at a map and seeing the pH of each location.” Although O’Grady is testing her drifter in the Boston Harbor, her intent is to create a design that may be used in almost any river across the country. The maps that her device ultimately produces will serve to paint a better picture of how river water is incorporated into the ocean.

This project was spurred by the combined interests and career goals held by O’Grady, who has always been keen to marine science and conservation. As a Mechanical Engineering major at MIT, she is merging multiple aspects of her life into the development of a single device. Looking ahead, O’Grady anticipates being a rising sophomore with multiple commitments, which include being a member of the swim team and dormitory advisory board.

The drifter’s testing and development consumed most of her attention this summer with the highlight of the summer being her successful retrieval of her drifter after it’s maiden voyage.

""