Nitrate supply from deep to near-surface waters of the North Pacific subtropical gyre

Nature ◽  
2010 ◽  
Vol 465 (7301) ◽  
pp. 1062-1065 ◽  
Author(s):  
Kenneth S. Johnson ◽  
Stephen C. Riser ◽  
David M. Karl
Keyword(s):  
Surface Waters ◽  
North Pacific ◽  
Subtropical Gyre ◽  
North Pacific Subtropical Gyre ◽  
Near Surface ◽  
The North ◽  
Nitrate Supply ◽  
The North Pacific

scholarly journals Diel population dynamics and mortality of Prochlorococcus in the North Pacific Subtropical Gyre

2021 ◽  
Author(s):  
Stephen J Beckett ◽  
David Demory ◽  
Ashley R Coenen ◽  
John R Casey ◽  
Mathilde Dugenne ◽  
...  
Keyword(s):  
North Pacific ◽  
Large Scale ◽  
Size Structure ◽  
Subtropical Gyre ◽  
Heterotrophic Nanoflagellates ◽  
Model Data ◽  
North Pacific Subtropical Gyre ◽  
Near Surface ◽  
The North ◽  
The North Pacific

Marine ecosystem models often consider temporal dynamics on the order of months to years, and spatial dynamics over regional and global scales as a means to understand the ecology, evolution, and biogeochemical impacts of marine life. Large-scale dynamics are themselves driven over diel scales as a result of light-driven forcing, feedback, and interactions. Motivated by high-frequency measurements taken by Lagrangian sampling in the North Pacific Subtropical Gyre, we develop a hierarchical set of multitrophic community ecology models to investigate and understand daily ecological dynamics in the near-surface ocean including impacts of light-driven growth, infection, grazing, and phytoplankton size structure. Using these models, we investigate the relative impacts of viral-induced and grazing mortality for Prochlorococcus; and more broadly compare in silico dynamics with in situ observations. Via model-data fitting, we show that a multi-trophic model with size structure can jointly explain diel changes in cyanobacterial abundances, cyanobacterial size structure, viral abundance, viral infection rates, and grazer abundances. In doing so, we find that a significant component (between 5% to 55%) of estimated Prochlorococcus mortality is not attributed to either viral lysis (by T4- or T7-like cyanophage) or grazing by heterotrophic nanoflagellates. Instead, model-data integration suggests a heightened ecological relevance of other mortality mechanisms -- including grazing by other predators, particle aggregation, and stress-induced loss mechanisms. Altogether, linking mechanistic multitrophic models with high-resolution measurements provides a route for understanding of diel origins of large-scale marine microbial community and ecosystem dynamics.

scholarly journals Wind and sunlight shape microbial diversity in surface waters of the North Pacific Subtropical Gyre

2015 ◽  
Vol 10 (6) ◽  
pp. 1308-1322 ◽  
Author(s):  
Jessica A Bryant ◽  
Frank O Aylward ◽  
John M Eppley ◽  
David M Karl ◽  
Matthew J Church ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Surface Waters ◽  
North Pacific ◽  
Subtropical Gyre ◽  
North Pacific Subtropical Gyre ◽  
The North ◽  
The North Pacific

scholarly journals Planktonic Archaeal Ether Lipid Origins in Surface Waters of the North Pacific Subtropical Gyre

2021 ◽  
Vol 12 ◽  
Author(s):  
Fuyan Li ◽  
Andy Leu ◽  
Kirsten Poff ◽  
Laura T. Carlson ◽  
Anitra E. Ingalls ◽  
...  
Keyword(s):  
Surface Waters ◽  
Lipid Composition ◽  
North Pacific ◽  
Ether Lipid ◽  
Subtropical Gyre ◽  
Ether Lipids ◽  
North Pacific Subtropical Gyre ◽  
The North ◽  
Tetraether Lipids ◽  
The North Pacific

Thaumarchaeota and Thermoplasmatota are the most abundant planktonic archaea in the sea. Thaumarchaeota contain tetraether lipids as their major membrane lipids, but the lipid composition of uncultured planktonic Thermoplasmatota representatives remains unknown. To address this knowledge gap, we quantified archaeal cells and ether lipids in open ocean depth profiles (0–200 m) of the North Pacific Subtropical Gyre. Planktonic archaeal community structure and ether lipid composition in the water column partitioned into two separate clusters: one above the deep chlorophyll maximum, the other within and below it. In surface waters, Thermoplasmatota densities ranged from 2.11 × 106 to 6.02 × 106 cells/L, while Thaumarchaeota were undetectable. As previously reported for Thaumarchaeota, potential homologs of archaeal tetraether ring synthases were present in planktonic Thermoplasmatota metagenomes. Despite the absence of Thaumarchaeota in surface waters, measurable amounts of intact polar ether lipids were found there. Based on cell abundance estimates, these surface water archaeal ether lipids contributed only 1.21 × 10–9 ng lipid/Thermoplasmatota cell, about three orders of magnitude less than that reported for Thaumarchaeota cells. While these data indicate that even if some tetraether and diether lipids may be derived from Thermoplasmatota, they would only comprise a small fraction of Thermoplasmatota total biomass. Therefore, while both MGI Thaumarchaeota and MGII/III Thermoplasmatota are potential biological sources of archaeal GDGTs, the Thaumarchaeota appear to be the major contributors of archaeal tetraether lipids in planktonic marine habitats. These results extend and confirm previous reports of planktonic archaeal lipid sources, and further emphasize the need for Thermoplasmatota cultivation, to better characterize the membrane lipid constituents of marine planktonic Thermoplasmatota, and more precisely define the sources and patterns of archaeal tetraether lipid distributions in marine plankton.

scholarly journals Euphotic zone metabolism in the North Pacific Subtropical Gyre based on oxygen dynamics

2020 ◽  
Author(s):  
Sara Ferron ◽  
Benedetto Barone ◽  
Matthew J Church ◽  
Angelicque E. White ◽  
David M. Karl
Keyword(s):  
North Pacific ◽  
Euphotic Zone ◽  
Subtropical Gyre ◽  
North Pacific Subtropical Gyre ◽  
The North ◽  
Oxygen Dynamics ◽  
The North Pacific

Weakening and Poleward Shifting of the North Pacific Subtropical Fronts from 1980 to 2018

2021 ◽  
Keyword(s):  
Mixed Layer ◽  
North Pacific ◽  
Subtropical Gyre ◽  
Hadley Cell ◽  
North Pacific Subtropical Gyre ◽  
Mode Water ◽  
Mode Waters ◽  
The North ◽  
The North Pacific ◽  
Subtropical Fronts

Abstract Recent evidence shows that the North Pacific subtropical gyre, the Kuroshio Extension (KE) and Oyashio Extension (OE) fronts have moved poleward in the past few decades. However, changes of the North Pacific Subtropical Fronts (STFs), anchored by the North Pacific subtropical countercurrent in the southern subtropical gyre, remain to be quantified. By synthesizing observations, reanalysis, and eddy-resolving ocean hindcasts, we show that the STFs, especially their eastern part, weakened (20%±5%) and moved poleward (1.6°±0.4°) from 1980 to 2018. Changes of the STFs are modified by mode waters to the north. We find that the central mode water (CMW) (180°-160°W) shows most significant weakening (18%±7%) and poleward shifting (2.4°±0.9°) trends, while the eastern part of the subtropical mode water (STMW) (160°E-180°) has similar but moderate changes (10% ± 8%; 0.9°±0.4°). Trends of the western part of the STMW (140°E-160°E) are not evident. The weakening and poleward shifting of mode waters and STFs are enhanced to the east and are mainly associated with changes of the northern deep mixed layers and outcrop lines—which have a growing northward shift as they elongate to the east. The eastern deep mixed layer shows the largest shallowing trend, where the subduction rate also decreases the most. The mixed layer and outcrop line changes are strongly coupled with the northward migration of the North Pacific subtropical gyre and the KE/OE jets as a result of the poleward expanded Hadley cell, indicating that the KE/OE fronts, mode waters, and STFs change as a whole system.

scholarly journals 2P271 Flow cytometry identification of nanocyanobacteria and their limiting factors in the North Pacific Subtropical Gyre(23. Ecology & Environment,Poster)

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S203
Author(s):  
Mathias Girault ◽  
Hisayuki Arakawa ◽  
Gerald Gregori ◽  
Fuminori Hashihama ◽  
Hyonchol Kim ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
North Pacific ◽  
Subtropical Gyre ◽  
Limiting Factors ◽  
North Pacific Subtropical Gyre ◽  
The North ◽  
The North Pacific
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