Stewardship Monday: The Ocean and the Climate
How is the ocean related to the climate? The ocean plays a major role in regulating weather and climate across the globe. This concept is so important that understanding it is a key part of NOAA’s standards for “Ocean Literacy”. I will quote the whole standard below for reference while the website is unavailable due to the government shutdown:
Ocean Literacy Standard 3: The ocean is a major influence on weather and climate.
a. The ocean controls weather and climate by dominating the Earth’s energy, water and carbon systems.
b. The ocean absorbs much of the solar radiation reaching Earth. The ocean loses heat by evaporation. This heat loss drives atmospheric circulation when, after it is released into the atmosphere as water vapor, it condenses and forms rain. Condensation of water evaporated from warm seas provides the energy for hurricanes and cyclones.
c. The El Nino Southern Oscillation causes important changes in global weather patterns because it changes the way heat is released to the atmosphere in the Pacific.
d. Most rain that falls on land originally evaporated from the tropical ocean.
e. The ocean dominates the Earth’s carbon cycle. Half the primary productivity on Earth takes place in the sunlit layers of the ocean and the ocean absorbs roughly half of all carbon dioxide added to the atmosphere.
f. The ocean has had, and will continue to have, a significant influence on climate change by absorbing, storing, and moving hear, carbon and water.
g. Changes in the ocean’s circulation have produced large, abrupt changes in climate during the last 50,000 years.
This topic is very complex and involves many factors, but here I will discuss some fundamentals to get you started in your ocean literacy.
Understanding the “Water Cycle” is the first step in understanding the role of the ocean in climate. There are songs and even dances that teach us: evaporation, condensation and precipitation. Of course, there are a few steps in between, but those basic functions drive the cycle and explain why the ocean, which holds 70% of the earth’s water, is so important. Every cloud, gust of wind or sprinkle of rain is influenced by the sea.
Evaporation: water molecules with adequate energy (from sun, wind, friction, etc) “escape” the surface of a liquid and become a gas (evaporative cooling is the effect of escaping/releasing heat/energy through evaporation—this is why your skin dries faster in the sun, and feels cooler when there is a breeze)
Condensation: the opposite of evaporation, the change from gas to liquid when the vapor comes into contact with any surface
Precipitation: the product of condensation that falls (under the force of gravity), also known as rain, sleet, snow, or hail—this occurs when there air is cool or there is a saturation of water vapor in the air.
Another important concept that you may intuitively be familiar with, which is important in climate, is that heat rises. So, as warm water evaporates and rises into the atmosphere it is leaving a space, or a low pressure area (a term you may hear on the weather report), which draws in cooler air along the surface—this is what creates wind, as well as drives atmospheric circulation.
Water is also unique in that it can absorb a lot of heat without getting hot very quickly (it has a high heat capacity). In other words, it takes a lot of energy to raise even a small amount of water by one degree. This is one reason why areas near large bodies of water (such as here on the California coast) have temperate and “Mediterranean” climates.
In addition to influencing energy absorption and water cycle, the ocean has an important role in the carbon cycle. As discussed in last week’s Stewardship Monday, carbon dioxide is a greenhouse gas that has had a big effect in climate change. The ocean plays a part in absorbing and cycling this molecule through chemical and organic processes such as photosynthesis, respiration, and consumption. As atmospheric carbon dioxide increases, the amount of the gas that the ocean has to process increases, with serious effects that will be discussed in next week’s post.
Thinking about this week’s topic always has impressed me with how tremendous and how tremendously important the ocean is. Every day, no matter how close to the shore I am, my life is influenced by the ocean. As an extension of that, every day my life is affected by how healthy the ocean is and how the whole world is taking care of it.
Stewardship challenge of the week: record every time you are being influenced by the ocean, because of the weather or because you are using a product from the ocean, or even if you make a new friend because you share a common interest in the ocean.