Rising temperatures to make oceans bluer and greener

Katie Ramirez
February 5, 2019

The study predicts that the blues will intensify, most likely in subtropical regions where phytoplankton will decrease.

"Ocean color will give us an earlier signal of climate change effects on the marine ecosystem than other things we usually look at", said Stephanie Dutkiewicz, a biogeochemist at Massachusetts Institute of Technology in Cambridge, who led the new research.

The oceans appear blue because water molecules alone absorb nearly all sunlight except for the blue part of the spectrum, but with any organism in the ocean, phytoplankton for instance, the pigment in it will absorb less in the green portions and reflect more green light.

Hickman said: "Crudely speaking, where the water is now quite blue because the phytoplankton [have a] relatively low biomass, you are going to see the water getting more blue, and where the ocean is relatively more green because the biomass is higher, you are going to see [it] getting [greener]".

"There will be a noticeable difference in the colour of 50 percent of the ocean by the end of the 21st century", Dr Dutkiewicz said. "That basic pattern will still be there".

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans.

Numbers of phytoplankton in areas such as the subtropics are predicted to fall, causing oceans to take on a much bluer colour.

For their study, the researchers developed a model simulating the growth and interactions of different phytoplankton species, and ran simulations based on the planet warming by 3C. "We are interested in phytoplankton because they are tiny marine plants, they contribute about half of global photosynthesis, they are the base of the marine food web". The deeper green hues will reveal larger blooms of more diverse phytoplankton resulting in higher levels of aquatic life.

It’s wrong of Krish to attack me: Kangana Ranaut
Manikarnika has earned approximately Rs 5.30 crore on Monday and on Tuesday the movie has earned Rs 5 crore approximately. Talking about the controversy, As reported by Pinkvilla, Kangana said, "It is wrong of Krish to attack me like that".

They serve as food to many aquatic animals but can also become risky.

Since the late 1990s, satellites have taken continuous measurements of the ocean's color.

This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region. By looking at these measurements, the level of chlorophyll can be determined, which could be due to global warming or weather-related phenomena, such as an El Niño or La Niña, Dutkiewicz said.

"Sunlight will come into the ocean, and anything that's in the ocean will absorb it, like chlorophyll", Dutkiewicz says.

For Mr. Strutton, "What this study has shown is that although the greenness of the oceans, the amount of chlorophyll might only be changing by small amounts, what's important is that the type of phytoplankton might be changing more dramatically".

The team, which includes researchers from MIT, University of Southhampton, National Oceanography Centre Southampton, University of California at Santa Cruz, and University of California at Davis, states that the new model shows that the effects of climate change on the oceans is far more rapid than expected.

But in the scientific world, they could mean significant shifts.

When they increased the global temperatures by up to 3 degrees Celsius by 2100, they found that wavelengths of light in the blue or green wave band responded the fastest. As such, life in these areas as we know it today is likely to also change. "By the end of the century, our blue planet may look visibly altered", wrote Jennifer Chu in the press release.

Other reports by

Discuss This Article