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13. Trace Metal Dynamics in Shallow Hydrothermal Plumes at the Kermadec Arc

Author

Kleint, Charlotte, Zitoun, Rebecca, Neuholz, René, Walter, Maren, Schnetger, Bernhard, Klose, Lukas, Chiswell, Stephen M., Middag, Rob, Laan, Patrick, Sander, Sylvia G., Koschinsky, Andrea, Kleint, Charlotte, Zitoun, Rebecca, Neuholz, René, Walter, Maren, Schnetger, Bernhard, Klose, Lukas, Chiswell, Stephen M., Middag, Rob, Laan, Patrick, Sander, Sylvia G., and Koschinsky, Andrea

Abstract

Hydrothermal vents are a source of many trace metals to the oceans. Compared to mid-ocean ridges, hydrothermal vent systems at arcs occur in shallower water depth and are much more diverse in fluid composition, resulting in highly variable water column trace metal concentrations. However, only few studies have focused on trace metal dynamics in hydrothermal plumes at volcanic arcs. During R/V Sonne cruise SO253 in 2016/2017, hydrothermal plumes from two hydrothermally active submarine volcanoes along the Kermadec arc in the Southwest Pacific Ocean were sampled: (1) Macauley, a magmatic dominated vent site located in water depths between 300 and 680 m, and (2) Brothers, located between 1,200 and 1,600 m water depth, where hydrothermalism influenced by water rock interactions and magmatically influenced vent sites occur near each other. Surface currents estimated from satellite-altimeter derived currents and direct measurements at the sites using lowered acoustic Doppler current profilers indicate the oceanic regime is dominated by mesoscale eddies. At both volcanoes, results indicated strong plumes of dissolved trace metals, notably Mn, Fe, Co, Ni, Cu, Zn, Cd, La, and Pb, some of which are essential micronutrients. Dissolved metal concentrations commonly decreased with distance from the vents, as to be expected, however, certain element/Fe ratios increased, suggesting a higher solubility of these elements and/or their stronger stabilization (e.g., for Zn compared to Fe). Our data indicate that at the magmatically influenced Macauley and Brothers cone sites, the transport of trace metals is strongly controlled by sulfide nanoparticles, while at the Brothers NW caldera wall site iron oxyhydroxides seem to dominate the trace metal transport over sulfides. Solution stabilization of trace metals by organic complexation appears to compete with particle adsorption processes. As well as extending the generally sparse data set for hydrothermal plumes at volcanic arc systems

Published
2022
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17. Trace Metal Dynamics in Shallow Hydrothermal Plumes at the Kermadec Arc

Author

Kleint, Charlotte, primary, Zitoun, Rebecca, additional, Neuholz, René, additional, Walter, Maren, additional, Schnetger, Bernhard, additional, Klose, Lukas, additional, Chiswell, Stephen M., additional, Middag, Rob, additional, Laan, Patrick, additional, Sander, Sylvia G., additional, and Koschinsky, Andrea, additional

Published
2022
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25. Corrigendum: Off-target capture data, endosymbiont genes and morphology reveal a relict lineage that is sister to all other singing cicadas

Author

Simon, Chris, primary, Gordon, Eric R L, additional, Moulds, M S, additional, Cole, Jeffrey A, additional, Haji, Diler, additional, Lemmon, Alan R, additional, Lemmon, Emily Moriarty, additional, Kortyna, Michelle, additional, Nazario, Katherine, additional, Wade, Elizabeth J, additional, Meister, Russell C, additional, Goemans, Geert, additional, Chiswell, Stephen M, additional, Pessacq, Pablo, additional, Veloso, Claudio, additional, McCutcheon, John P, additional, and Łukasik, Piotr, additional

Published
2019
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26. Off-target capture data, endosymbiont genes and morphology reveal a relict lineage that is sister to all other singing cicadas

Author

Simon, Chris, primary, Gordon, Eric R L, additional, Moulds, M S, additional, Cole, Jeffrey A, additional, Haji, Diler, additional, Lemmon, Alan R, additional, Lemmon, Emily Moriarty, additional, Kortyna, Michelle, additional, Nazario, Katherine, additional, Wade, Elizabeth J, additional, Meister, Russell C, additional, Goemans, Geert, additional, Chiswell, Stephen M, additional, Pessacq, Pablo, additional, Veloso, Claudio, additional, McCutcheon, John P, additional, and Łukasik, Piotr, additional

Published
2019
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28. Physical oceanography of New Zealand/Aotearoa shelf seas – a review.

Author

Stevens, Craig L., O'Callaghan, Joanne M., Chiswell, Stephen M., and Hadfield, Mark G.

Subjects
OCEANOGRAPHY, REGIONS of freshwater influence, OCEANIC mixing
Abstract

The shelf seas surrounding New Zealand/Aotearoa, a region nominally extending out to the 250 m depth contour, are complex and varied as they sit above the submerged continent of Zealandia. These seas surround the two main islands that span 1,500 km in latitude from 34°S to 47°S and include a series of plateaus that extend far beyond. This review summarises the present state of knowledge of the physical processes that control ocean transport and mixing in this domain. The focus is on documenting recent regional advances in understanding the balance between off-shelf drivers, terrestrially sourced freshwater, winds, tides, stratification and the underlying topography. The review considers outstanding themes such as connectivity, climate and stratification and closes with an assessment of the potential future for understanding the physical marine environment of the shelf seas of the New Zealand region. [ABSTRACT FROM AUTHOR]

Published
2021
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29. Five years' central Pacific sea level from in situ array, satellite altimeter and numerical model

Author

Donohue, Kathleen A, Wimbush, Mark, Zhu, Xiaoli, Chiswell, Stephen M, Lukas, Roger, Miller, Laury, and Hurlburt, Harley E

Subjects
Oceanography
Abstract

Temporal and spatial fetures of central equatorial Pacific Ocean sea-level variation appear similar, in measurements from two very different systems (one in the ocean and one carried on a satellite), and in results from a numerical model of the region. In particular, there is an interannual cycle: during El Nino, Kelvin waves appear at the equator, and the sea-surface ridge associated with the equatorial current system shifts southward; in non-El Nino years, instability waves appear at 6 deg N (strongest around the end of each calendar year), and the ridge shifts to the north. This three-way comparison gives support to both measurement systems and to the numerical model.

Published
1994

30. The periodical cicada four-year acceleration hypothesis revisited and the polyphyletic nature of Brood V, including an updated crowd-source enhanced map (Hemiptera: Cicadidae: Magicicada)

Author

Cooley, John R., primary, Arguedas, Nidia, additional, Bonaros, Elias, additional, Bunker, Gerry, additional, Chiswell, Stephen M., additional, DeGiovine, Annette, additional, Edwards, Marten, additional, Hassanieh, Diane, additional, Haji, Diler, additional, Knox, John, additional, Kritsky, Gene, additional, Mills, Carolyn, additional, Mozgai, Dan, additional, Troutman, Roy, additional, Zyla, John, additional, Hasegawa, Hiroki, additional, Sota, Teiji, additional, Yoshimura, Jin, additional, and Simon, Chris, additional

Published
2018
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34. Exploring mechanisms for spring bloom evolution: contrasting 2008 and 2012 blooms in the southwest Pacific Ocean.

Author

Chiswell, Stephen M, Safi, Karl A, Sander, Sylvia G, Strzepek, Robert, Ellwood, Michael J, Milne, Angela, and Boyd, Philip W

Subjects
*SPRINGS (Mechanisms), *ALGAL blooms, *OCEAN, *CHLOROPHYLL, *BIOLOGICAL evolution
Abstract

Observations from two research cruises made in 2008 and 2012 to east of New Zealand are put into context with satellite data to contrast and compare surface chlorophyll a evolution in the two years in order to explore mechanisms of phytoplankton bloom development in the southwest Pacific Ocean. In 2008, surface chlorophyll a largely followed the long-term climatological cycle, and 2008 can be considered a canonical year, where the autumn bloom is triggered by increasing vertical mixing at the end of summer and the spring bloom is triggered by decreasing vertical mixing at the end of winter. In contrast, 2012 was anomalous in that there was no autumn bloom, and in early spring there were several periods of sustained increase in surface chlorophyll a that did not become fully developed spring blooms. (In this region, we consider spring blooms to occur when surface chlorophyll a exceeds 0.5 mg m-3). These events can be related to alternating episodes of increased or decreased vertical mixing. The eventual spring bloom in October was driven by increased ocean cooling and wind stress (i.e. increased mixing) and paradoxically was driven by mechanisms considered more appropriate for autumn rather than spring blooms. [ABSTRACT FROM AUTHOR]

Published
2019
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39. Drifter- and float-derived mean circulation at the surface and 1000 m in the New Zealand region

Author

Chiswell, Stephen M, Sutton, Philip JH, Chiswell, Stephen M, and Sutton, Philip JH

Abstract

Global Drifter Program (GDP) drifter data and Argo float data from 2006 to 2013 are used to provide quantitative description and comparison of the mean near-surface (15 m) and 1000 m velocity fields in the New Zealand region. These fields are estimated both from bin-averaging the drifter/float velocities and by fitting non-divergent streamfunctions to the velocities. At both levels, our velocity fields are broadly consistent with previous drifter/float estimates, but provide more detail on the local structure of the mean fields. North of the Subantarctic Front there are large differences between the surface and 1000 m flows, with the Tasman Front being largely absent at 1000 m. South of the Subantarctic Front, where the flow is expected to be more barotropic, there is a closer correspondence between the flows at both levels. Several previously undocumented eddies in the mean flows at both levels are described.

Published
2015
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41. The Distribution of Periodical Cicada (Hemiptera: Cicadidae:Magicicada) Brood II in 2013: Disjunct Emergences Suggest Complex Brood Origins

Author

Cooley, John R., primary, Simon, Chris, additional, Maier, Chris T., additional, Marshall, David, additional, Yoshimura, Jin, additional, Chiswell, Stephen M., additional, Edwards, Marten, additional, Holliday, Chuck, additional, Grantham, Richard, additional, Zyla, John, additional, Sanders, Robert L., additional, Neckermann, Michael, additional, and Bunker, Gerry, additional

Published
2015
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42. Climatology of surface chlorophyll , autumn-winter and spring blooms in the southwest Pacific Ocean

Author

Chiswell, Stephen M., Bradford-Grieve, Janet, Hadfield, Mark G., and Kennan, Sean C.

Subjects
Chlorophyll a, Deep chlorophyll maximum, Wind stress, Spring bloom, Oceanography, Annual cycle, chemistry.chemical_compound, Geophysics, chemistry, Space and Planetary Science, Geochemistry and Petrology, Climatology, Earth and Planetary Sciences (miscellaneous), Environmental science, Subtropical front, Bloom, Thermocline
Abstract

[1] Ocean color data from the 13 year Sea-viewing Wide Field-of-view Sensor mission are used to examine the distribution of surface chlorophyll a in the southwest Pacific Ocean. The mean surface chlorophyll field is similar to that found by previous workers, with elevated levels in the Subtropical Front and around the subantarctic islands that have an associated shelf. The annual cycle in surface chlorophyll shows a ubiquitous summer bloom in subantarctic water, with autumn, winter, and spring blooms variously in subtropical water and across the Subtropical Front. The autumn blooms progress equatorward with time at the same rate as wind stress. This supports the idea that the autumn bloom develops in response to increased wind stress, with a likely mechanism for the bloom being mixing to the surface of the deep chlorophyll maximum, and/or increased production due to entrainment of nutrients. The spring bloom progresses poleward with time. It starts after the mixed layer reaches its deepest, and its timing appears to be linked to the reduction in wind stress in spring. Under the assumption that all tracers are well mixed to the seasonal thermocline in autumn and winter, we conclude that vertically integrated chlorophyll increases at all latitudes in subtropical water during autumn and winter. Unfortunately, carbon-to-chlorophyll ratios are not known well enough to determine whether the same is true for vertically integrated carbon biomass. Individual spring blooms show significant spatial structure and are different from year to year. This leads to low spatial coherence for the temporal variability in surface chlorophyll.

Published
2013
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43. Wind-driven upwelling and surface chlorophyll blooms in Greater Cook Strait.

Author

Chiswell, Stephen M., Zeldis, John R., Hadfield, Mark G., and Pinkerton, Matthew H.

Subjects
*WATER, *CHLOROPHYLL, *UPWELLING (Oceanography)
Abstract

We present the results of a combined observational and numerical study to investigate cool plumes of nutrient-rich upwelled water that emanate near the Kahurangi Shoals and extend into Greater Cook Strait. Surface temperature and chlorophyll are mapped using satellite observations to produce surface climatologies, to validate a numerical simulation and to show the utility of using spatial temperature differences as a measure of upwelling. We find upwelling near the Kahurangi Shoals is strongly wind-driven in the weather band. Upwelling occurs at all times of the year, but its surface signature is only visible in summer months. The upwelled nutrient-rich water supports increased primary production compared to surrounding waters, particularly in summer when the water column is more stratified and surrounding surface waters are presumably nutrient depleted. [ABSTRACT FROM AUTHOR]

Published
2017
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