Award: OCE-1924394

This award developed a new tool to understand how gases (including carbon dioxide) are trapped in the ocean, and how these gases can be released to the atmosphere. Because the ocean holds about 50 times more carbon dioxide than the atmosphere, even a small release of this gas can have a substatial impact on climate. The new tool involves the noble gases, which include xenon, krypton, argon, and neon. Noble gases have the great advantage that they are simple, and do not undergo any chemical reactions in nature. This simplicity makes it much easier to understand their behavior in the ocean, and ultimately to apply the knowledge gained from them to more-complex gases like carbon dioxide. The unique aspect of the this award was that it used the isotopes of noble gases for the first time; an isotope is simply an atom with an extra neutron, making it heavier but not changing its chemical behavior. For example, xenon has nine isotopes, all with slightly different ability to dissolve in water. A longstanding puzzle has been the degree to which carbon dioxide is released to the atmosphere when CO2-rich water from the deep ocean upwells to the surface. The main issue is that it takes about a year for this CO2-rich water to outgas to the atmosphere, and come to chemical equilbrium with the overlying air. Yet it is well known that these CO2-rich waters often stay at the surface only a month or less before they are forced back into the deep ocean, which is far too short a time for the waters to dicharge their load of CO2. This is part of the reason that the ocean has 50 times more CO2 than the atmosphere; the ocean "holds on" to the CO2. In other words, the ocean's CO2 is in a state of disequilibrium with the atmosphere. By using noble gases, which are very simple and easy to interpret, this award laid the groundwork for future efforts to better quantify how much disequilibrium exists in the dissolved CO2 in the ocean. Ultimately, this knowledge will help us predict how much of humanity's CO2 production will end up trapped in the ocean, where it cannot cause further climate warming. Last Modified: 10/25/2022 Submitted by: Jeffrey P Severinghaus