Wednesday, May 2, 2012

Let’s Talk Science! Cycle through our Ecology for Scientists web portal

By Brook Beeler, Environmental Educator, Office of Communication and Education

Did you know that Ecology has a web portal for all you hard core science types? It is a one stop shop for links to our monitoring databases, mapping and spatial data, and the most recent scientific reports and articles. Good science provides the foundation for credible decision-making. And we want you to have access.
But before you dive into the latest postings on Microbial Source Tracking, macroinvertebrates in the Wenatchee River, or the latest update to our Eyes Over Puget Sound monitoring, let’s talk science.

You may have heard that our oceans are a large “carbon sink,” meaning they absorb and store carbon. Before checking out our information on the state’s ocean acidification Blue Ribbon Panel, linked from our scientist’s page, learn about the carbon cycle. Understanding the carbon cycle is important because as the oceans soak up higher levels of carbon emissions, the chemistry of the seawater changes — both locally and globally. This carbon absorption alters the ocean’s natural water quality balance.

The Carbon Cycle

Diagram of the carbon cycle. The black numbers indicate how much carbon is stored in various reservoirs, in billions of tons ("GtC" stands for gigatons of carbon and figures are circa 2004). The dark blue numbers indicate how much carbon moves between reservoirs each year. (image source Wikipedia)
The earth is one incredible and dynamic system; and within this system there are processes that function in cycles. Just like a bicycle tire, round and round they go. On a larger scale, there is the rock cycle and water cycle and on the elemental level there is the nitrogen cycle and carbon cycle. All of these cycles are cruising along, interacting with one another to create a beautiful system we call home.

Let’s start with understanding one of these cycles. The carbon cycle allows carbon to be recycled and reused throughout the earth’s many systems and among all of its organisms. The major pathways for carbon are:
  • Atmosphere — layer of gases that surround the earth
  • Biosphere — living organisms on earth
  • Geosphere — the earth itself
  • Hydrosphere — the combined amount of water on the earth
Carbon is constantly being exchanged between these pathways through chemical, physical, geological and biological processes. Some pathways exchange carbon more readily than others. When carbon is not rapidly exchanging through these pathways, it is stored in what is known as a carbon reservoir. 

A Deeper Look

Carbon exchange between the atmosphere and the earth’s oceans is particularly interesting because the ocean is the largest reservoir of carbon. You can divide this reservoir into two pools. The ocean contains the largest active pool of exchangeable carbon near its surface, but the deep ocean part of this pool does not rapidly exchange. In regions of oceanic upwelling, carbon is released to the atmosphere. Conversely, regions of downwelling transfer carbon in the form of carbon dioxide (CO2) from the atmosphere to the ocean.

When CO2 enters the ocean it undergoes a series of chemical reactions changing from dissolved carbon dioxide gas into carbonic acid, bicarbonate, then carbonate. As the carbon changes forms, hydrogen ions are released into the ocean. At this point, the different forms of carbon are now exchanging through other pathways in the cycle, including being absorbed into sediment, living organisms or back into the atmosphere, continuing the carbon recycling process.

But what about those hydrogen ions released into the ocean due to carbon cycling? As the concentration of hydrogen ions increases, the water chemistry of our oceans change. One way scientists verify this change in water chemistry is by measuring the pH of ocean water. pH is a measure of the concentration of hydrogen ions in any solution. The higher the concentration, the more acidic the solution. When an increase in hydrogen ions occurs in the oceans, the pH decreases. This change is known as ocean acidification.

As carbon dioxide increases in the atmosphere, how will Washington State be affected? Our scientists are part of a panel to answer that question. To learn more about the science and actions in Washington state visit our “Ecology for Scientists” web portal and link to the ocean acidification Blue Ribbon Panel.

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