The brand new remote sensation: NASA studies our oceans from afar

Over 100 students filed into Science 120 last Thursday, March 3, for the International Ocean-Colour Coordinating Group (IOCCG) and NASA seminar: "Using Remote Sensing to Study Oceans." Four lecturers of various research backgrounds united to discuss how data gathered from satellites and aircraft is being used to monitor and study their common interest: the ecology of our oceans.

“In the late 1970s, an experimental satellite was launched and put into space and started producing images,” said Stewart Bernard, chair of the IOCCG and principal researcher for the Council for Scientific and Industrial Research in Cape Town.

By knowing what substances influence the color of water — from the chlorophyll in phytoplankton resulting in a turbid green or sediment creating a light brown — scientists can distinguish these various regions.

“Then you go and map the whole world,” Bernard said. “You can see how the global ocean is functioning and responding to changes.”

“I never knew why bodies of water were different colors,” business student Jamie Laber said. “How amazing that different species is what can make part of the ocean a bright red.”

Heidi Dierssen, an associate professor and head of the Coastal Ocean Laboratory for Optics and Remote Sensing in the Department of Marine Sciences and Geography at the University of Connecticut, is using color data from remote sensors to evaluate sea grass.

Sea grass acts as a nursery for fisheries and plays an essential role in our ecosystem. “[Sea grass] can actually indicate whether your water body is healthy or not," Dierssen said. However, they are currently being decimated globally.

“We don’t know how many sea grass fields there are,” Dierssen said. “We need to start assessing these habitats — how much we lost, how much there are.”

Working with the NASA’s Jet Propulsion Laboratory, they built sensors that can penetrate deep enough to map the color of the bottom of the water where the sea grass grows. Using aircraft equipped with this technology, they are able to find and monitor sea grass fields.

“I thought it was amazing,” aerospace engineering student Raul Mercado said. “Knowing you can get this satellite data and infiltrate what’s going on in our oceans to be able to see if our sea grass and ocean is clean.”

Satellite color data is also being used to help with fish assessment. While satellites can’t see fish directly, phytoplankton, which is the base of the ocean food web, can be used to predict the amount and location of fish.

“To a certain degree, you can say chlorophyll equals fish,” said Cara Wilson, a satellite oceanographer for the Environmental Research Division at the National Ocean and Atmospheric Administration’s (NOAA) Southwest Fisheries Science Center in Monterey, California and principal investigator for the West Coast branch of NOAA’s CoastWatch program.

NOAA is responsible for managing over 450 fish stocks, which includes assessing and predicting fish populations, setting catch limits and finding ways to rebuild depleted stocks. Using information from satellites, they are able to maximize field surveys by targeting optimal locations.

In addition to evaluating sea and ocean life, satellite data is used to monitor water quality and track events such as oil spills, runoff and algae blooms.

“Water quality monitoring isn’t as good as it should be,” said Paul DiGiacomo, manager of the NOAA CoastWatch/OceanWatch Program and manager of the Marine Optical Buoy Project.

Storm water runoff in areas like Southern California brings pollutants and pathogens into our beaches, resulting in coastal closures due to bacteria and toxins. Satellite data is used to follow the runoff and determine the best locations to conduct water quality tests. Combining this information with models of ocean currents, they are able to predict its flow.

“Satellite remote sensing provides invaluable data on coastal and ocean dynamics and ecosystems,” said DiGiacomo. “But it needs to be coupled with field measurements and models to maximize its utility to support water quality research and other applications.”

He ended the seminar emphasizing the importance for the next generation of scientists and researchers, highlighting the need to expand on and discover new ways of monitoring and protecting our oceans.