The Cooperative Institute for Climate, Ocean, and Ecosystem Studies

My name is Theo Daniels, and I am a Biology and Political Science double major at Howard University in Washington, D.C. Working with chemical oceanographer, Bonnie Chang, and physical oceanographer, Noel Pelland, my project focused on determining what the measurements of trace gases such as oxygen and nitrous oxide look like for each season across a variety of longitudinal coordinates, -110 W, -150 W, -168 W. These coordinates corresponded with the GO-SHIP research cruises that my mentor Bonnie has been on in the region the past few years. Nitrous oxide data analyzed from those ships tell a different story than what was originally hypothesized.

Although a smaller greenhouse gas, nitrous oxide is extremely potent, doing about 300 times as much damage than the more prominent carbon dioxide. In recent years, nitrous oxide has garnered more recognition and research, but our understanding on the gas pales in comparison to others. To further analyze my mentor’s GO-SHIP nitrous oxide data, we first need to find a good benchmark for comparison such as the World Ocean Atlas (WOA) datasets. The only problem with that is the WOA does not explicitly measure for nitrous oxide as a part of their popularized 2018 dataset. The bulk of this internship centered around finding a viable link to relate the GO-SHIP and WOA datasets to make nitrous oxide comparisons.

The data shown on this poster focuses on the P18 GO-SHIP research cruise from the Fall/Winter of 2017, located at the edge of an Oxygen Deficient Zone (OMZ) off the coast of Peru. These zones are areas in the ocean in which the water is considered “old” and poorly circulated, resulting in an abnormally low oxygen level throughout. Prior research tells us that within these ODZs, a process called nitrification occurs with great aplomb, one of the byproducts being the nitrous oxide we are now looking to account for.

One common data point held between the GO-SHIP and WOA data is the oxygen concentration measured in micromoles per kilogram. We figured that if the two datasets showed enough similarity with the plots that would be made in MATLAB, a linear regression model could be used to determine an equation that would be used to make nitrous oxide proxy maps with the WOA data. The regression model we were able to derive from the GO-SHIP data was the relationship between nitrous oxide and the concentration of oxygen. Using a plethora of equations on MATLAB gathered from leading experts in chemical and physical oceanography allowed us to determine that there are great similarities between the World Ocean Atlas and GO-SHIP datasets. The next steps will be to construct the WOA nitrous oxide proxy maps and continue an analysis of these gases in the focus region of the Pacific Ocean.

A special thank you to Bonnie, Noel, Jed, Haley, and the entire CICOES team for such an amazing summer experience.

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