CO2 Sensors in the Ocean

By janani – Posted on 22 August 2011

Measuring CO2 in the ocean provides a wealth of information into the state of oceanic life and earth.

The CO2 absorbed from the atmosphere clues us in to the magnitude of the greenhouse effect, as well as the temperature of the water. It also provides information as to how the level of CO2 changes with time and how plant and wildlife is affected by an amount of CO2.

CO2 measurement is a time-consuming process which requires the researcher to take samples of water, transport them to the lab, and titrate. Dr. Ge and other members of the CAST lab have created a sensor consisting of a gas permeable membrane that takes pH measurements to determine CO2 levels. In this sensor, the water sample will enter the membrane and the gas will diffuse into a pH sensitive dye. The pH measurements are then sent to a lab that can mathematically correlate it to CO2.

The electronics involved in the project are also very innovative. The sensor, along with sensors for oxygen and temperature, will be placed in a 1’ x 1’ floatable device that will be placed in the ocean. The data collected from the sensors in the device will be wirelessly transmitted to a buoy that will send the information to a nearby lab on shore, where the calculations from pH to CO2 can be made. Thus, the sensor has the ability to make quick, efficient, accurate readings in waters that are miles away.