Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Impact Of Diatom-Diazotroph Associations On Carbon Export In The Amazon River Plume, Ly Yeung, Wm Berelsen, Et Al, Deborah K. Steinberg, Et Al
Impact Of Diatom-Diazotroph Associations On Carbon Export In The Amazon River Plume, Ly Yeung, Wm Berelsen, Et Al, Deborah K. Steinberg, Et Al
VIMS Articles
Offshore tropical river plumes are associated with areas of high N-2 fixation (diazotrophy) and biological carbon drawdown. Episodic blooms of the diatom Hemiaulus hauckii and its diazotrophic cyanobacterial symbiont Richelia intracellularis are believed to dominate that carbon drawdown, but the mechanism is not well understood. We report primary productivity associated with blooms of these diatom-diazotroph assemblages (DDAs) in the offshore plume of the Amazon River using simultaneous measurements of O-2/Ar ratios and the triple-isotope composition of dissolved O-2. In these blooms, we observe peaks in net community productivity, but relatively small changes in gross primary productivity, suggesting that DDA blooms …
Chlorophyll A In Antarctic Sea Ice From Historical Ice Core Data, Km Meiners, M Vancoppenolle, S Thanassekos, Gs Dieckmann, Dn Thomas, .. .., Walker O. Smith Jr., Et Al
Chlorophyll A In Antarctic Sea Ice From Historical Ice Core Data, Km Meiners, M Vancoppenolle, S Thanassekos, Gs Dieckmann, Dn Thomas, .. .., Walker O. Smith Jr., Et Al
VIMS Articles
Sea ice core chlorophyll a data are used to describe the seasonal, regional and vertical distribution of algal biomass in Southern Ocean pack ice. The Antarctic Sea Ice Processes and Climate - Biology (ASPeCt - Bio) circumpolar dataset consists of 1300 ice cores collected during 32 cruises over a period of 25 years. The analyses show that integrated sea ice chlorophyll a peaks in early spring and late austral summer, which is consistent with theories on light and nutrient limitation. The results indicate that on a circum-Antarctic scale, surface, internal and bottom sea ice layers contribute equally to integrated biomass, …
Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa
Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa
VIMS Articles
Significant strides in our understanding of the marine pelagic ecosystem of the Western Antarctic Peninsula (WAP) region have been made over the past two decades, resulting from research conducted aboard ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer. These advances range from an understanding of the physical forcing on biology, to food web ecology (from microbes to top predators), to biogeochemical cycling, often in the larger context of rapid climate warming in the region. The proximity of the WAP to the Antarctic Circumpolar Current and WAP continental shelf bathymetry affects the hydrography and helps structure the biological community. Seasonal, …
Isotopic Characterization Of Aerosol Organic Carbon Components Over The Eastern United States, A. S. Wozniak, James E. Bauer, Rebecca M. Dickhut, Li Xu, Ann P. Mcnichol
Isotopic Characterization Of Aerosol Organic Carbon Components Over The Eastern United States, A. S. Wozniak, James E. Bauer, Rebecca M. Dickhut, Li Xu, Ann P. Mcnichol
VIMS Articles
Carbon isotopic signatures (delta C-13, Delta C-14) of aerosol particulate matter total organic carbon (TOC) and operationally defined organic carbon (OC) components were measured in samples from two background sites in the eastern U. S. TOC and water-soluble OC (WSOC) delta C-13 values (-27 to -24 parts per thousand) indicated predominantly terrestrial C-3 plant and fossil derived sources. Total solvent extracts (TSE) and their aliphatic, aromatic, and polar OC components were depleted in delta C-13 (-30 to -26 parts per thousand) relative to TOC and WSOC. Delta C-14 signatures of aerosol TOC and TSE (-476 to +25 parts per thousand) …