Carbonated Oceans (2021 Version)

Summary

This video script explores the gases dissolved in the ocean, primarily nitrogen, oxygen, and carbon dioxide. It delves into the processes of photosynthesis, respiration, and decomposition, explaining how they affect gas concentrations. Carbon dioxide, with its high solubility, is the most abundant gas in the ocean, influencing the water's carbonation levels. The script also covers the impact of temperature, pressure, and salinity on gas solubility and the buffering system that maintains ocean pH. Additionally, it discusses how increased carbon dioxide from both natural and human sources leads to ocean acidification, affecting marine life and ecosystems.

Takeaways

• 😀 The top three gases dissolved in the ocean are nitrogen, oxygen, and carbon dioxide.
• 😀 Gases in the ocean come from several sources including the atmosphere, underwater volcanoes, and biological processes like photosynthesis, respiration, and decomposition.
• 😀 Photosynthesis in the ocean produces oxygen and removes carbon dioxide, making it a key process for ocean gas balance.
• 😀 Respiration uses up oxygen and releases carbon dioxide, which is crucial for understanding ocean gas cycles.
• 😀 Decomposition also contributes to carbon dioxide production, as bacteria break down organic material.
• 😀 Carbon dioxide has the highest solubility in the ocean, making it the most abundant gas dissolved in seawater, unlike in the atmosphere.
• 😀 Gas solubility in the ocean changes with temperature and salinity, influencing carbonation levels at different depths.
• 😀 Carbonation in the ocean is highest at greater depths due to lower temperatures, higher pressure, and higher solubility of gases.
• 😀 The ocean’s pH is regulated by a buffering chemical reaction involving carbon dioxide, carbonic acid, bicarbonate, and carbonate ions.
• 😀 The increase in carbon dioxide in the atmosphere and oceans is lowering ocean pH, contributing to ocean acidification, which affects marine organisms with calcium carbonate shells.
• 😀 As ocean acidity increases, shells made of calcium carbonate dissolve below a certain depth known as the carbonate compensation depth (CCD).

Q & A

What are the top three gases dissolved in the ocean?

The top three gases dissolved in the ocean are nitrogen, oxygen, and carbon dioxide.

How do gases get into the ocean?

Gases enter the ocean through several sources, including the atmosphere, volcanic outgassing from underwater volcanoes, and biological processes such as respiration, decomposition, and photosynthesis.

What is the process of photosynthesis, and how does it affect ocean gases?

Photosynthesis involves water combining with carbon dioxide and energy from light to produce sugar, releasing oxygen as a byproduct. This process removes carbon dioxide from the ocean and adds oxygen, serving as a major oxygen source and a carbon dioxide sink.

How does respiration differ from photosynthesis?

Respiration is the reverse of photosynthesis. In respiration, organisms burn sugar with oxygen to produce energy, and in the process, carbon dioxide and water are released, using up oxygen and contributing to the increase of carbon dioxide in the ocean.

What role does decomposition play in ocean gas dynamics?

Decomposition is similar to respiration in that it breaks down organic material, such as dead organisms, using oxygen and producing carbon dioxide, thus contributing to the carbon dioxide concentration in the ocean.

Which gas is the most abundant in the ocean, and why?

Carbon dioxide is the most abundant gas in the ocean due to its high solubility in water, unlike oxygen and nitrogen, which are less soluble.

How do temperature and salinity affect gas solubility in the ocean?

Gas solubility in the ocean is influenced by temperature and salinity. Lower temperatures and higher salinity increase gas solubility, while warmer temperatures and lower salinity reduce it.

Why does carbonation vary in different types of water?

Carbonation varies depending on the type of water. For example, carbon dioxide is more soluble in pure water (like seltzer), while the presence of sugar or salt in sodas reduces the solubility of carbon dioxide, leading to less carbonation.

What is the carbonate compensation depth (CCD) in the ocean?

The carbonate compensation depth (CCD) is the depth in the ocean below which calcium carbonate shells begin to dissolve due to increased carbon dioxide concentration and acidity, preventing carbonate-shelled organisms from surviving at these depths.

How does increased carbon dioxide affect the ocean's pH?

Increased carbon dioxide leads to more carbonic acid in the ocean, which dissociates to release hydrogen ions (H+), causing the ocean's pH to decrease (becoming more acidic). This is a key factor contributing to ocean acidification.