Upper Ocean Methane Dynamics - Annual Report
Abstract
LONG TERM GOALS. 1. Determine the temporal and spatial variability of the stable carbon isotopic ratios of oceanic methane (CH4), paying particular attention to coastal regions and other areas of high productivity. 2. Elucidate the details of CH4 production and consumption in the upper ocean. 3. Determine the importance of terrestrial sources to the oceanic CH4 cycle. OBJECTIVES. The objectives of this project are to provide a better understanding of the carbon cycle in the ocean and to allow estimation of the carbon isotopic composition of methane exchanging with the atmosphere from surface waters. Estimates of the oceanic component of global CH4 models can thereby be better constrained. This work is supported by ONR Chemical Oceanography. APPROACH. In order to achieve the above mentioned long-term goals, the isotopic signature of CH4 produced by plankton and in particulate matter, which may be the source of the observed CH4 supersaturation in open ocean surface waters, will be determined. The temporal and vertical spatial variability of CH4 in the upper ocean are also investigated. In addition, the isotopic composition of CH4 in coastal waters and nearby oligotrophic surface waters have been compared in order to elucidate the spatial and temporal importance of CH4 production and consumption processes across this transition zone. Finally, the degree of equilibrium between the atmosphere and the surface ocean for CH4 fugacity and isotopic are determined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1997
- Accession Number
- ADA634294
Entities
People
- Brian N. Popp
- Francis J. Sansone
Organizations
- University of Hawaiʻi System