Ferrous iron and hydrogen peroxide produced by marine aerosols deposited in ocean water of the Equatorial Pacific Ocean
Document Type
Oral Presentation
Campus where you would like to present
SURC Ballroom C/D
Start Date
16-5-2013
End Date
16-5-2013
Abstract
The Equatorial Pacific Ocean is limited in primary productivity by the micronutrient iron, which is delivered to the ocean through the deposition of continental aerosols. Despite the fact that the amount and speciation of this iron controls phytoplankton productivity and thus has implications on the carbon cycle and global climate, accurate estimates of the atmospheric contribution of bioavailable iron to the surface ocean are difficult to obtain. To further our understanding of reactions that transform iron after it is deposited into the ocean we performed photochemical experiments using real collected aerosol particles in real ocean water. Subnanomolar levels of ferrous iron (Fe(II)) and hydrogen peroxide (H2O2) were determined with chemiluminescence detection in the presence of luminol and acridinium ester, respectively. Fe(II) and H2O2 increased in the presence of light during the course of the dissolution experiments and spiked with the addition of dimethyl sulfide, which is a compound emitted by phytoplankton when under stress such as iron limitation. These results show that Fe(II), which is found to be more bioavailable than its oxidized counterpart, is produced by compounds that are co-deposited with aerosol particles as well as compounds directly emitted by phytoplankton. These mechanisms of iron redox cycling in surface ocean waters allow us to better predict the impact of changing aerosol loadings on the carbon and sulfur cycles and global climate.
Recommended Citation
Teng, Hsiang and Ting, Hoi, "Ferrous iron and hydrogen peroxide produced by marine aerosols deposited in ocean water of the Equatorial Pacific Ocean" (2013). Symposium Of University Research and Creative Expression (SOURCE). 55.
https://digitalcommons.cwu.edu/source/2013/posters/55
Poster Number
51
Additional Mentoring Department
Chemistry
Ferrous iron and hydrogen peroxide produced by marine aerosols deposited in ocean water of the Equatorial Pacific Ocean
SURC Ballroom C/D
The Equatorial Pacific Ocean is limited in primary productivity by the micronutrient iron, which is delivered to the ocean through the deposition of continental aerosols. Despite the fact that the amount and speciation of this iron controls phytoplankton productivity and thus has implications on the carbon cycle and global climate, accurate estimates of the atmospheric contribution of bioavailable iron to the surface ocean are difficult to obtain. To further our understanding of reactions that transform iron after it is deposited into the ocean we performed photochemical experiments using real collected aerosol particles in real ocean water. Subnanomolar levels of ferrous iron (Fe(II)) and hydrogen peroxide (H2O2) were determined with chemiluminescence detection in the presence of luminol and acridinium ester, respectively. Fe(II) and H2O2 increased in the presence of light during the course of the dissolution experiments and spiked with the addition of dimethyl sulfide, which is a compound emitted by phytoplankton when under stress such as iron limitation. These results show that Fe(II), which is found to be more bioavailable than its oxidized counterpart, is produced by compounds that are co-deposited with aerosol particles as well as compounds directly emitted by phytoplankton. These mechanisms of iron redox cycling in surface ocean waters allow us to better predict the impact of changing aerosol loadings on the carbon and sulfur cycles and global climate.
Faculty Mentor(s)
Anne Johansen