| Contributors | Affiliation | Role |
|---|---|---|
| Trull, Tom W. | Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) | Principal Investigator |
| Bray, Stephen | Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) | Co-Principal Investigator |
| Chandler, Cynthia L. | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
IRS sediment trap fluxes
(see platform deployments)
(see platform deployments)
| Parameter | Description | Units |
| date | date sampling began (GMT) | YYYYMMDD |
| event | unique sampling event | dimensionless |
| ev_code | event code from cruise log | alphanumeric |
| lon | longitude, negative denotes West | decimal degs |
| lat | latitude, negative denotes South | decimal degs |
| cruise_deployment | cruise and tether deployment number | text |
| cup | IRS cup number | dimensionless |
| sinking_rate_fraction | cup 1 has >820 m/d, cup 2 has 410 to 820 m/day etc | m per day |
| cup_duration_per_cycle | time each cup is under funnel, each cycle of ball valve | minutes |
| PC_flux_tot_per_cup | total particulate carbon flux | umol/m2/day |
| PIC_flux_per_cup | particulate inorganic carbon flux | umol/m2/day |
| PC_flux_per_cup | particulate carbon (calculated by difference PC-PIC) flux | umol/m2/day |
| PN_flux_per_cup | particulate nitrogen flux | umol/m2/day |
| Bsi_flux_per_cup | biogenic silica flux | umol/m2/day |
| PC_flux_per_cup_duration | flux normalized to cup duration (as the longer a cup is open the more it can collect) | umol/m2/day/min |
| POC_K2_1_swimmers | K2-1 POC contents of zooplankton removed from the samples and analysed separately | umol/m2/day |
| PC_flux_fraction | % PC in cup of total POC in trap | percent |
| PC_flux_cumulative_fraction | % PC in cup and all preceding cups of total POC in trap | percent |
| POC_to_PN | molar ratio | dimensionless ratio |
| PO_to_PIC | molar ratio (=mass ratio as have carbon/carbon) | dimensionless ratio |
| PC_to_POC | molar ratio | dimensionless ratio |
| PC_to_BSi | molar ratio bd indicates below detectable limit or bad data | dimensionless ratio |
| Dataset-specific Instrument Name | IRS Sediment Trap |
| Generic Instrument Name | Sediment Trap - IRS |
| Generic Instrument Description | Sediment traps are specially designed containers deployed in the water column for periods of time to collect particles from the water column falling toward the sea floor. In general a sediment trap has a jar at the bottom to collect the sample and a broad funnel-shaped opening at the top with baffles to keep out very large objects and help prevent the funnel from clogging. The Indented Rotating Sphere (IRS) Sediment Trap is described in Peterson et al. (Field evaluation of a valved sediment trap. 1993. Limnology and Oceanography, 38, pp. 1741-1761 and Novel techniques for collection of sinking particles in the ocean and determining their settling rates. 2005. Limnology and Oceanography Methods 3, pp. 520-532). The IRS trap consists of four cylindrical modules; a particle interceptor, an IRS valve; a skewed funnel, and an eleven sample carousel (designated IRSC trap). The key to the trap design is the patented IRS valve located between the particle interceptor and particle accumulator portions of the trap. The valve and carousel are regulated by a TattleTale IVA (manufactured by Onset Computer Corp.) microprocessor and custom software. The IRS sediment trap was specifically designed to exclude zooplankton (Trull et al. 2008. Deep-Sea Research II v.55 pp. 1684-1695). |
| Website | |
| Platform | R/V Kilo Moana |
| Start Date | 2004-06-20 |
| End Date | 2004-07-10 |
| Description | VERTIGO project expedition to the U.S. Hawaii Ocean Time-series (HOT) site, near the deep-water Station ALOHA (A Long-Term Oligotrophic Habitat Assessment; 22° 45'N, 158° 00'W) located 100 km north of Oahu, Hawaii. Funded by: NSF OCE-0301139
Related information:
VERTIGO cruise information from the VERTIGO Project site: https://cafethorium.whoi.edu/projects/vertigo/vertigo-hi/
HOT Web site: https://hahana.soest.hawaii.edu/index.html
Original cruise data are available from the NSF R2R data catalog: http://www.rvdata.us/catalog/KM0414 Methods & Sampling Methodology: Methodology Change history: YYMMDD 080709: contributed by Tom Trull 081110: added to OCB database; Steve Gegg (sgegg@whoi.edu), BCO DMO 081125: date, event, ev_code, lat, lon added from cruise event log (ev_code: Trull_Arr_D2 = cruise-deployment: Trull IRS Aloha Deployment #2) KM0414 event log 090209: minor edits to some parameter names to conform to OCB convention |
| Website | |
| Platform | R/V Roger Revelle |
| Start Date | 2005-07-21 |
| End Date | 2005-08-27 |
| Description | VERTIGO 2005 expedition to the K2site in the NW Pacific near 45° N and 160° E
Funded by: NSF OCE-0301139
Cruise information from the VERTIGO project site: https://cafethorium.whoi.edu/projects/vertigo/vertigo-k2/
Original cruise data for the Revelle are available from the NSF R2R data catalog: http://www.rvdata.us/catalog/ZHNG09RR Methods & Sampling Methodology: Methodology Change history: YYMMDD 080709: contributed by Tom Trull 081110: added to OCB database; Steve Gegg (sgegg@whoi.edu), BCO DMO 081125: date, event, ev_code, lat, lon added from cruise event log (ev_code: Trull-Trap_I = cruise-deployment: K2-1) (ev_code: Trull-Trap_2_I = cruise-deployment: K2-2) RR_K2 event log 090209: minor edits to some parameter names to conform to OCB convention |
NSF Award Abstract:
In this study, researchers at the Woods Hole Oceanographic Institution, Virginia Institute of Marine Science, University of California - Santa Cruz, University of California - Santa Barbara, University of Tasmania, and NIWA-Australia will work collaboratively to answer a difficult question in marine biogeochemistry: What controls the efficiency of particle transport between the surface and deep ocean? More specifically, what is the fate of sinking particles leaving the upper ocean and what factors influence remineralization length scales for different sinking particle classes? Knowing the efficiency of particle transport is important for an accurate assessment of the ocean carbon sink. Globally, the magnitude and efficiency of the biological pump will in part modulate levels of atmospheric carbon dioxide.
The research team intends to test two basic hypotheses about remineralization control, namely: (1) particle source characteristics are the dominant control on the efficiency of particle transport; and/or that (2) mid-water processing, either by zooplankton or bacteria, controls transport efficiency. To do so, they will conduct process studies at sea focused on particle flux and composition changes in the upper 500-1000m of the ocean. The basic approach is to examine changes in particle composition and flux with depth within a given source region using a combination of approaches, many of which are new to the field. These include neutrally buoyant sediment traps, particle pumps, settling columns and respiration chambers, along with the development of new biological and geochemical tools for an integrated biogeochemical assessment of the biological pump. Two sites will be studied extensively on three-week process study cruises: the Hawaii Ocean Time-series site (HOT) and a new moored time-series site in the subarctic NW Pacific (Japanese site K2; 47oN 160oE). There are strong contrasts between these sites in rates of production, export, particle composition and expected remineralization length scales.
Evidence for variability in the flux vs. depth relationship of sinking particles is not in dispute, but the controls on particle transport efficiency through the twilight zone remain poorly understood. A lack of reliable flux and particle characterization data within the twilight zone has hampered our ability to make progress in this area, and no single approach is likely to resolve these issues. The proposed study will apply quantitative modeling to determine the net effects of the individual particle processes on the effective transport of carbon and other elements and to place the shipboard observations in the context of spatial and temporal variations in these processes
Besides the obvious contributions to the study of the oceanic and planetary carbon cycles, there are broader outcomes and impacts forthcoming from this project. Graduate and undergraduate students will be included in all aspects of the research, and the involvement of non-US PIs will encourage exchange of students and post-docs between labs in different countries. In addition, the component groups will continue to maintain science web sites designed for both public and scientific exchange where the broader and specific goals and outcomes of this work can be communicated.
Original PI-provided project description:
The main goal of VERTIGO is the investigation of the mechanisms that control the efficiency of particle transport through the mesopelagic portion of the water column.
Question: What controls the efficiency of particle transport between the surface and deep ocean? More specifically, what is the fate of sinking particles leaving the upper ocean and what factors influence remineralization length scales for different sinking particle classes? VERTIGO researchers have set out to test two basic hypotheses regarding remineralization control, namely:
1. particle source characteristics are the dominant control on the efficiency of particle transport; and/or that
2. mid-water processing, either by zooplankton or bacteria, controls transport efficiency.
To test their hypotheses, they will conduct process studies in the field focused on particle flux and composition changes in the upper 500-1000m of the ocean. The basic approach is to examine changes in particle composition and flux with depth within a given source region using a combination of approaches, many of which are new to the field. These include neutrally buoyant sediment traps, particle pumps, settling columns and respiration chambers, along with the development of new biological and geochemical tools for an integrated biogeochemical assessment of the biological pump. Three week process study cruises have been planned at two sites - the Hawaii Ocean Time-series site (HOT) and a new moored time-series site in the subarctic NW Pacific (Japanese site K2; 47oN 160oE) - where there are strong contrasts in rates of production, export, particle composition and expected remineralization length scales.
Evidence for variability in the flux vs. depth relationship of sinking particles is not in dispute but the controls on particle transport efficiency through the twilight zone remain poorly understood. A lack of reliable flux and particle characterization data within the twilight zone has hampered our ability to make progress in this area, and no single approach is likely to resolve these issues. The proposed study will apply quantitative modeling to determine the net effects of the individual particle processes on the effective transport of carbon and other elements, and to place the shipboard observations in the context of spatial and temporal variations in these processes. For rapid progress in this area, we have organized this effort as a group proposal taking advantage of expertise in the US and international community.
The efficiency of particle transport is important for an accurate assessment of the ocean C sink. Globally, the magnitude and efficiency of the biological pump will in part modulate levels of atmospheric CO2. We maintain that to understand present day ocean C sequestration and to evaluate potential strategies for enhancing sequestration, we need to assess possible changes in the efficiency of particle transport due to climate variability or via purposeful manipulations of C uptake, such as via iron fertilization.
VERTIGO Acknowledgments: (from K.O. Buesseler, et al / Deep-Sea Research II 55 (2008) 1522-1539) We thank the officers, crew and shore-based support teams for the R/V Kilo Moana (2004) and R/V Roger Revelle (2005). Funding for VERTIGO was provided primarily by research grants from the US National Science Foundation Programs in Chemical and Biological Oceanography (KOB, CHL, MWS, DKS, DAS). Additional US and non-US grants included: US Department of Energy, Office of Science, Biological and Environmental Research Program (JKBB); the Gordon and Betty Moore Foundation (DMK); the Australian Cooperative Research Centre program and Australian Antarctic Division (TWT); Chinese NSFC and MOST programs (NZJ); Research Foundation Flanders and Vrije Universiteit Brussel (FD, ME); JAMSTEC (MCH); New Zealand Public Good Science Foundation (PWB); and internal WHOI sources and a contribution from the John Aure and Cathryn Ann Hansen Buesseler Foundation (KOB). A number of individuals at sea and on shore, helped make the VERTIGO project a success, including: J. Andrews, C. Bertrand, R. Bidigare III, S. Bray, K. Casciotti, M. Charette, R. Condon, J. Cope, E. Fields, M. Gall, M. Gonneea, P. Henderson, T. Kobari, D. Kunz, S. Saitoh, S. Manganini, C. Moy, S. Okamoto, S. Pike, L. Robertson, D. Ruddick and Y. Zhang. Suggestions by three anonymous reviewers and help by the editor, R. Lampitt, are also greatly appreciated.
The Ocean Carbon and Biogeochemistry (OCB) program focuses on the ocean's role as a component of the global Earth system, bringing together research in geochemistry, ocean physics, and ecology that inform on and advance our understanding of ocean biogeochemistry. The overall program goals are to promote, plan, and coordinate collaborative, multidisciplinary research opportunities within the U.S. research community and with international partners. Important OCB-related activities currently include: the Ocean Carbon and Climate Change (OCCC) and the North American Carbon Program (NACP); U.S. contributions to IMBER, SOLAS, CARBOOCEAN; and numerous U.S. single-investigator and medium-size research projects funded by U.S. federal agencies including NASA, NOAA, and NSF.
The scientific mission of OCB is to study the evolving role of the ocean in the global carbon cycle, in the face of environmental variability and change through studies of marine biogeochemical cycles and associated ecosystems.
The overarching OCB science themes include improved understanding and prediction of: 1) oceanic uptake and release of atmospheric CO2 and other greenhouse gases and 2) environmental sensitivities of biogeochemical cycles, marine ecosystems, and interactions between the two.
The OCB Research Priorities (updated January 2012) include: ocean acidification; terrestrial/coastal carbon fluxes and exchanges; climate sensitivities of and change in ecosystem structure and associated impacts on biogeochemical cycles; mesopelagic ecological and biogeochemical interactions; benthic-pelagic feedbacks on biogeochemical cycles; ocean carbon uptake and storage; and expanding low-oxygen conditions in the coastal and open oceans.