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Colors of the Ocean: Why Are Some Oceans Blue and Others Green?
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Colors of the Ocean: Why Are Some Oceans Blue and Others Green?

Wave Tribe

Because we feel the need to break down the common misconceptions behind every color of our oceans.

Published by Wave Tribe

The blue tint of the ocean is proven to be therapeutic, the reason why most people are drawn to it.

There are moments in life when you want nothing but to be in the company of oceans. They induce a meditative state that makes us calm and happier, which also explains why we love going to different beaches to keep ourselves sane. The oceans are proven to have therapeutic power. They are people’s paradise to unwind, to free themselves from stressors by doing water activities, or simply sitting by the seashore to enjoy the sight of waves. That being said, you might be wondering what contributes to this transformational effect. Does it have to do with the color of the ocean being blue?

Would the effect be the same if the ocean’s typical color was never blue, but some other color such as violet or pink? It would be beautiful. Perhaps, it reminds you of magic and unicorns, but blue seascapes are more calming. Scientific research from Richard Shuster shows that just being near the color blue has led to “an overwhelming amount of people to be associated with feelings of calm and peace.” Staring out at the ocean can result in a relaxing, meditative state and can even change the frequency of brain waves to match that of the sea, putting you in touch with nature.

Have you ever wondered why the ocean has a blue tone or why it is sometimes another color, specifically green? Why does the sea sometimes look dark blue, sometimes light blue, other times more of green color? To answer this question, we first need to understand why water typically appears blue. Here's the science behind the colors of the ocean.​

Here's what you can find in this article:

There's a science involved behind the blue and green tint of some of our oceans.

It's said that everything in this world has a science behind it, and I believe so, including the ocean's colors. It is way more essential to know the reasons behind what's occurring more than believing what we are not certain of. At the end of the day, the condition of our oceans is our responsibility.

— Derek Dodds, Wave Tribe Founder

Colors of the Ocean: Why is the Ocean Blue?

If you are familiar with or have heard of Raleigh scattering in one of your Science courses, that phenomenon explains why the sky is blue—to explain it simply, the atmosphere tends to scatter shorter wavelength (blue) light to a greater extent than longer wavelength (red) light. Blue light from the sun is scattered every which way, much more so than some other colors. So, when we look up at the sky, we see blue.

However, during sunset and sunrise, the angle at which sunlight enters the atmosphere is drastically changed, and most of the green and blue wavelengths of light are scattered even before reaching the lower atmosphere, so in this case, we see more of the red and orange colors in the sky.

If you’ve believed that the ocean is blue because some of the blue light from the sky is reflected, then you must be well-read. This is a perfect opportunity to confirm its contribution. But mainly, it is the absorption of longer wavelength (red) light. In water, absorption is strong in the red and weak in the blue. Thus red light is absorbed quickly in the ocean, making it reflect blue. When the light hits the sea, the molecules present in water absorb some photons from the light.

The absorption of longer wavelength (red) light makes the ocean appear blue.

In the case of deeper waters, not all the wavelengths of light can completely penetrate the liquid. There are too many water molecules in the way of the photons. This explains why shallower waters have a lighter blue tint than deeper ones. Less absorption means less reflection.

You can relate the color of the ocean and the color of the sky. However, they exist independently of each other. In both cases, the absorption of longer wavelength (red) light makes the blue color. As for the water, the absorption of red light only works if the liquid is pure. Otherwise, the light scattered off algae, mud, or other impurities present in the ocean will overwhelm the water’s blue tint.

Colors of the Ocean: Why Are Others Green?

Phytoplankton are microscopic, single-celled photosynthetic organisms that inhabit the upper sunlit layer of almost all oceans and freshwater bodies on Earth. It is the base of several aquatic food webs. Phytoplankton is the main reason why many scientists measure ocean color.

Chlorophyll is an essential light-absorbing substance in the oceans, which phytoplankton utilize in emitting carbon through photosynthesis. As we all know, chlorophyll is a green pigment, and it is due to this that phytoplankton can absorb the blue and red parts of the light spectrum and reflects green light. Chlorophyll soaks up the energy from sunlight, the reason why most marine and land plants are green.

Phytoplankton has different types as well as concentrations of chlorophyll. Thus, we can estimate the amount and type of phytoplankton present in the ocean based on its color. The greener it is, the higher the phytoplankton population it has. The color of the sea also indicates its chemistry and health.

The larger population of phytoplankton the ocean has, the greener it would appear.

Besides carbon dioxide and light, nutrients such as phosphorus and nitrogen are essentials for phytoplankton. We can detect where nutrient levels are high in the ocean based on plant distribution. Also, it indicates where pollutants prevent plant growth and poison the sea.

Phytoplankton is playing a tremendously important role here. The ocean fishing industries are also targeting areas that are rich in phytoplankton for fishing spots. How would they know? They look at the ocean’s color. Ocean color is, therefore, a valuable research tool for the study of ocean biology, chemistry, and physics.

Colors of the Ocean: Is A Murky Ocean Dirty?

So, why does the ocean have a dark blue tint in some places, lighter or turquoise in others, and sometimes more of a brown color which we deem dirty and look at it as though it is one of the grossest things on the planet?

Let’s get right on first with the dark and light tint, shall we? As mentioned earlier, shallower waters have a lighter blue shade than deeper ones. In deep water, the liquid absorbs almost all of the sunlight because of the lack of sediment, and only a tiny amount of organic matter such as algae is present. This simply explains why blue appears to be darker in deep oceans.

So, in regions with a high amount of phytoplankton, the ocean will appear in shades of green. It depends on the density and type of the phytoplankton present there. NASA reiterates that "the more phytoplankton in the water, the greener it is.... the less phytoplankton, the bluer it is." That pretty much simplified the answers to the questions as mentioned earlier.

Upwelling makes an ocean appear murky.

How about water with a tint of brown? Does it mean that it is not safe? Is it automatically dirty and filled with contaminants? Murkier water is an effect of upwelling. It is a process in which deep, cold water rises toward the surface and often occurs in the open ocean and along coastlines. In this case, the water has a high amount of floating sand churned up by waves, which explains the murky appearance. It can also be because of some other biological organisms that reflect light differently, causing its murkiness. Either way, there is nothing gross about it. It is just Science that is working behind all of these conditions.

Final Words

Stop having the notion that a blue ocean is a safe and clean ocean while a green or brown sea is not. In the real sense, the color of the sea does not entirely and certainly determine its safety and cleanliness. Do you know what does? Nothing other than the massive amount of garbage floating and killing marine life. You’d rather swim in a brown ocean than in a blue one that humans have treated as a dumping site.

So, the next time you come across a murkier or green ocean, it doesn’t necessarily mean that it’s gross, dirtier, or any less worthy of enjoying. Unless they are filled with plastics and garbage or considered the world’s dangerous oceans, they are safe and clean.

Here at Wave Tribe, we uphold the aim of going green and preserving the ecosystem for future generations; that is why we create eco-surfing products. We would be glad to gain support for our objectives by joining our Heal the Oceans campaign and practicing the utilization of economical materials that leave no harm to the environment or bodies of water. Learning about our eco-surfing products would be a great start for everyone.

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