1
|
Cael BB, Burger FA, Henson SA, Britten GL, Frölicher TL. Historical and future maximum sea surface temperatures. Sci Adv 2024; 10:eadj5569. [PMID: 38277447 PMCID: PMC10816719 DOI: 10.1126/sciadv.adj5569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 12/27/2023] [Indexed: 01/28/2024]
Abstract
Marine heat waves affect ocean ecosystems and are expected to become more frequent and intense. Earth system models' ability to reproduce extreme ocean temperature statistics has not been tested quantitatively, making the reliability of their future projections of marine heat waves uncertain. We demonstrate that annual maxima of detrended anomalies in daily mean sea surface temperatures (SSTs) over 39 years of global satellite observations are described excellently by the generalized extreme value distribution. If models can reproduce the observed distribution of SST extremes, this increases confidence in their marine heat wave projections. 14 CMIP6 models' historical realizations reproduce the satellite-based distribution and its parameters' spatial patterns. We find that maximum ocean temperatures will become warmer (by 1.07° ± 0.17°C under 2°C warming and 2.04° ± 0.18°C under 3.2°C warming). These changes are mainly due to mean SST increases, slightly reinforced by SST seasonality increases. Our study quantifies ocean temperature extremes and gives confidence to model projections of marine heat waves.
Collapse
Affiliation(s)
- B. B. Cael
- National Oceanography Centre, Southampton, UK
| | - Friedrich A. Burger
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | | | - Gregory L. Britten
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Thomas L. Frölicher
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| |
Collapse
|
2
|
de Melo Viríssimo F, Martin AP, Henson SA. Influence of Seasonal Variability in Flux Attenuation on Global Organic Carbon Fluxes and Nutrient Distributions. Global Biogeochem Cycles 2022; 36:e2021GB007101. [PMID: 35866103 PMCID: PMC9286473 DOI: 10.1029/2021gb007101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 12/22/2021] [Accepted: 01/07/2022] [Indexed: 06/15/2023]
Abstract
The biological carbon pump is a key component of the marine carbon cycle. This surface-to-deep flux of carbon is usually assumed to follow a simple power law function, which imposes that the surface export flux is attenuated throughout subsurface waters at a rate dictated by the parameterization exponent. This flux attenuation exponent is widely assumed as constant. However, there is increasing evidence that the flux attenuation varies both spatially and seasonally. While the former has received some attention, the consequences of the latter have not been explored. Here we aim to fill the gap with a theoretical study of how seasonal changes in both flux attenuation and sinking speed affect nutrient distributions and carbon fluxes. Using a global ocean-biogeochemical model that represents detritus explicitly, we look at different scenarios for how these varies seasonally, particularly the relative "phase" with respect to solar radiation and the "strength" of seasonality. We show that the sole presence of seasonality in the model-imposed flux attenuation and sinking speed leads to a greater transfer efficiency compared to the non-seasonal flux attenuation scenario, resulting in an increase of over 140% in some cases when the amplitude of the seasonality imposed is 60% of the non-seasonal base value. This work highlights the importance of the feedback taking place between the seasonally varying flux attenuation, sinking speed and other processes, suggesting that the assumption of constant-in-time flux attenuation and sinking speed might underestimate how much carbon is sequestered by the biological carbon pump.
Collapse
|
3
|
Abstract
The future response of marine ecosystem diversity to continued anthropogenic forcing is poorly constrained. Phytoplankton are a diverse set of organisms that form the base of the marine ecosystem. Currently, ocean biogeochemistry and ecosystem models used for climate change projections typically include only 2-3 phytoplankton types and are, therefore, too simple to adequately assess the potential for changes in plankton community structure. Here, we analyse a complex ecosystem model with 35 phytoplankton types to evaluate the changes in phytoplankton community composition, turnover and size structure over the 21st century. We find that the rate of turnover in the phytoplankton community becomes faster during this century, that is, the community structure becomes increasingly unstable in response to climate change. Combined with alterations to phytoplankton diversity, our results imply a loss of ecological resilience with likely knock-on effects on the productivity and functioning of the marine environment.
Collapse
Affiliation(s)
| | - B B Cael
- National Oceanography Centre, European Way, Southampton, UK
| | - Stephanie R Allen
- National Oceanography Centre, European Way, Southampton, UK
- School of Ocean and Earth Sciences, University of Southampton, Waterfront Campus, European Way, Southampton, UK
- Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
| | - Stephanie Dutkiewicz
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
4
|
Hammond ML, Beaulieu C, Henson SA, Sahu SK. Regional surface chlorophyll trends and uncertainties in the global ocean. Sci Rep 2020; 10:15273. [PMID: 32943692 PMCID: PMC7498587 DOI: 10.1038/s41598-020-72073-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 08/21/2020] [Indexed: 11/09/2022] Open
Abstract
Changes in marine primary productivity are key to determine how climate change might impact marine ecosystems and fisheries. Satellite ocean color sensors provide coverage of global ocean chlorophyll with a combined record length of ~ 20 years. Coupled physical–biogeochemical models can inform on expected changes and are used here to constrain observational trend estimates and their uncertainty. We produce estimates of ocean surface chlorophyll trends, by using Coupled Model Intercomparison Project (CMIP5) models to form priors as a “first guess”, which are then updated using satellite observations in a Bayesian spatio-temporal model. Regional chlorophyll trends are found to be significantly different from zero in 18/23 regions, in the range ± 1.8% year−1. A global average of these regional trends shows a net positive trend of 0.08 ± 0.35% year−1, highlighting the importance of considering chlorophyll changes at a regional level. We compare these results with estimates obtained with the commonly used “vague” prior, representing no independent knowledge; coupled model priors are shown to slightly reduce trend magnitude and uncertainties in most regions. The statistical model used here provides a robust framework for making best use of all available information and can be applied to improve understanding of global change.
Collapse
Affiliation(s)
- Matthew L Hammond
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK. .,Ocean and Earth Science, University of Southampton, Southampton, UK.
| | - Claudie Beaulieu
- Ocean and Earth Science, University of Southampton, Southampton, UK.,Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, USA
| | | | - Sujit K Sahu
- Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK
| |
Collapse
|
5
|
Belcher A, Henson SA, Manno C, Hill SL, Atkinson A, Thorpe SE, Fretwell P, Ireland L, Tarling GA. Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone. Nat Commun 2019; 10:889. [PMID: 30792498 PMCID: PMC6385259 DOI: 10.1038/s41467-019-08847-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/04/2019] [Indexed: 02/01/2023] Open
Abstract
The biological carbon pump drives a flux of particulate organic carbon (POC) through the ocean and affects atmospheric levels of carbon dioxide. Short term, episodic flux events are hard to capture with current observational techniques and may thus be underrepresented in POC flux estimates. We model the potential hidden flux of POC originating from Antarctic krill, whose swarming behaviour could result in a major conduit of carbon to depth through their rapid exploitation of phytoplankton blooms and bulk egestion of rapidly sinking faecal pellets (FPs). Our model results suggest a seasonal krill FP export flux of 0.039 GT C across the Southern Ocean marginal ice zone, corresponding to 17-61% (mean 35%) of current satellite-derived export estimates for this zone. The magnitude of our conservatively estimated flux highlights the important role of large, swarming macrozooplankton in POC export and, the need to incorporate such processes more mechanistically to improve model projections.
Collapse
Affiliation(s)
- A Belcher
- British Antarctic Survey, Cambridge, CB3 0ET, UK.
| | - S A Henson
- National Oceanography Centre, Southampton, SO14 3ZH, UK
| | - C Manno
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| | - S L Hill
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| | - A Atkinson
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - S E Thorpe
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| | - P Fretwell
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| | - L Ireland
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| | - G A Tarling
- British Antarctic Survey, Cambridge, CB3 0ET, UK
| |
Collapse
|
6
|
Cavan EL, Henson SA, Boyd PW. The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2018.00230] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
7
|
Bol R, Henson SA, Rumyantseva A, Briggs N. High-Frequency Variability of Small-Particle Carbon Export Flux in the Northeast Atlantic. Global Biogeochem Cycles 2018; 32:1803-1814. [PMID: 31007380 PMCID: PMC6472636 DOI: 10.1029/2018gb005963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 11/05/2018] [Accepted: 12/04/2018] [Indexed: 05/24/2023]
Abstract
The biological carbon pump exports carbon fixed by photosynthesis out of the surface ocean and transfers it to the deep, mostly in the form of sinking particles. Despite the importance of the pump in regulating the air-sea CO2 balance, the magnitude of global carbon export remains unclear, as do its controlling mechanisms. A possible sinking flux of carbon to the mesopelagic zone may be via the mixed-layer pump: a seasonal net detrainment of particulate organic carbon (POC)-rich surface waters, caused by sequential deepening and shoaling of the mixed layer. In this study, we present a full year of daily small-particle POC concentrations derived from glider optical backscatter data, to study export variability at the Porcupine Abyssal Plain (PAP) sustained observatory in the Northeast Atlantic. We observe a strong seasonality in small-particle transfer efficiency, with a maximum in winter and early spring. By calculating daily POC export driven by mixed-layer variations, we find that the mixed-layer pump supplies an annual flux of at least 3.0 ± 0.9 g POC·m-2·year-1 to the mesopelagic zone, contributing between 5% and 25% of the total annual export flux and likely contributing to closing a gap in the mesopelagic carbon budget found by other studies. These are, to our best knowledge, the first high-frequency observations of export variability over the course of a full year. Our results support the deployment of bio-optical sensors on gliders to improve our understanding of the ocean carbon cycle on temporal scales from daily to annual.
Collapse
Affiliation(s)
- Roséanne Bol
- School of Ocean and Earth SciencesUniversity of SouthamptonSouthamptonUK
- Now at NIOZ Royal Netherlands Institute for Sea ResearchTexelThe Netherlands
- Now at Department of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
| | | | - Anna Rumyantseva
- School of Ocean and Earth SciencesUniversity of SouthamptonSouthamptonUK
| | | |
Collapse
|
8
|
Henson SA, Cole HS, Hopkins J, Martin AP, Yool A. Detection of climate change-driven trends in phytoplankton phenology. Glob Chang Biol 2018; 24:e101-e111. [PMID: 28871605 DOI: 10.1111/gcb.13886] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 08/14/2017] [Indexed: 06/07/2023]
Abstract
The timing of the annual phytoplankton spring bloom is likely to be altered in response to climate change. Quantifying that response has, however, been limited by the typically coarse temporal resolution (monthly) of global climate models. Here, we use higher resolution model output (maximum 5 days) to investigate how phytoplankton bloom timing changes in response to projected 21st century climate change, and how the temporal resolution of data influences the detection of long-term trends. We find that bloom timing generally shifts later at mid-latitudes and earlier at high and low latitudes by ~5 days per decade to 2100. The spatial patterns of bloom timing are similar in both low (monthly) and high (5 day) resolution data, although initiation dates are later at low resolution. The magnitude of the trends in bloom timing from 2006 to 2100 is very similar at high and low resolution, with the result that the number of years of data needed to detect a trend in phytoplankton phenology is relatively insensitive to data temporal resolution. We also investigate the influence of spatial scales on bloom timing and find that trends are generally more rapidly detectable after spatial averaging of data. Our results suggest that, if pinpointing the start date of the spring bloom is the priority, the highest possible temporal resolution data should be used. However, if the priority is detecting long-term trends in bloom timing, data at a temporal resolution of 20 days are likely to be sufficient. Furthermore, our results suggest that data sources which allow for spatial averaging will promote more rapid trend detection.
Collapse
Affiliation(s)
| | | | - Jason Hopkins
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | | | - Andrew Yool
- National Oceanography Centre, Southampton, UK
| |
Collapse
|
9
|
Popova E, Yool A, Byfield V, Cochrane K, Coward AC, Salim SS, Gasalla MA, Henson SA, Hobday AJ, Pecl GT, Sauer WH, Roberts MJ. From global to regional and back again: common climate stressors of marine ecosystems relevant for adaptation across five ocean warming hotspots. Glob Chang Biol 2016; 22:2038-53. [PMID: 26855008 PMCID: PMC4999053 DOI: 10.1111/gcb.13247] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 11/20/2015] [Accepted: 12/16/2015] [Indexed: 05/18/2023]
Abstract
Ocean warming 'hotspots' are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2 -driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.
Collapse
Affiliation(s)
- Ekaterina Popova
- National Oceanography CentreU. Southampton Waterfront CampusSouthamptonSO14 3ZHUK
| | - Andrew Yool
- National Oceanography CentreU. Southampton Waterfront CampusSouthamptonSO14 3ZHUK
| | - Valborg Byfield
- National Oceanography CentreU. Southampton Waterfront CampusSouthamptonSO14 3ZHUK
| | | | - Andrew C. Coward
- National Oceanography CentreU. Southampton Waterfront CampusSouthamptonSO14 3ZHUK
| | - Shyam S. Salim
- Central Marine Fisheries Research InstitutePost Box No. 1603Ernakulam North P.O.Kochi‐682 018India
| | - Maria A. Gasalla
- Fisheries Ecosystems LaboratoryOceanographic InstituteUniversity of São PauloCidade UniversitáriaSão PauloSP05580‐120Brazil
| | - Stephanie A. Henson
- National Oceanography CentreU. Southampton Waterfront CampusSouthamptonSO14 3ZHUK
| | | | - Gretta T. Pecl
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaPO Box 49HobartTAS7001Australia
| | | | | |
Collapse
|
10
|
Henson SA, Beaulieu C, Lampitt R. Observing climate change trends in ocean biogeochemistry: when and where. Glob Chang Biol 2016; 22:1561-71. [PMID: 26742651 PMCID: PMC4785610 DOI: 10.1111/gcb.13152] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/12/2015] [Accepted: 10/19/2015] [Indexed: 05/21/2023]
Abstract
Understanding the influence of anthropogenic forcing on the marine biosphere is a high priority. Climate change-driven trends need to be accurately assessed and detected in a timely manner. As part of the effort towards detection of long-term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as pH, oxygen concentration or primary production (PP). Here, we use an ensemble of global coupled climate models to assess the temporal and spatial scales over which observations of eight biogeochemically relevant variables must be made to robustly detect a long-term trend. We find that, as a global average, continuous time series are required for between 14 (pH) and 32 (PP) years to distinguish a climate change trend from natural variability. Regional differences are extensive, with low latitudes and the Arctic generally needing shorter time series (<~30 years) to detect trends than other areas. In addition, we quantify the 'footprint' of existing and planned time series stations, that is the area over which a station is representative of a broader region. Footprints are generally largest for pH and sea surface temperature, but nevertheless the existing network of observatories only represents 9-15% of the global ocean surface. Our results present a quantitative framework for assessing the adequacy of current and future ocean observing networks for detection and monitoring of climate change-driven responses in the marine ecosystem.
Collapse
Affiliation(s)
| | - Claudie Beaulieu
- Ocean and Earth SciencesUniversity of SouthamptonEuropean WaySouthamptonSO14 3ZHUK
| | - Richard Lampitt
- National Oceanography CentreEuropean WaySouthamptonSO14 3ZHUK
| |
Collapse
|
11
|
Abstract
Sustained observations (SOs) have provided invaluable information on the ocean's biology and biogeochemistry for over 50 years. They continue to play a vital role in elucidating the functioning of the marine ecosystem, particularly in the light of ongoing climate change. Repeated, consistent observations have provided the opportunity to resolve temporal and/or spatial variability in ocean biogeochemistry, which has driven exploration of the factors controlling biological parameters and processes. Here, I highlight some of the key breakthroughs in biological oceanography that have been enabled by SOs, which include areas such as trophic dynamics, understanding variability, improved biogeochemical models and the role of ocean biology in the global carbon cycle. In the near future, SOs are poised to make progress on several fronts, including detecting climate change effects on ocean biogeochemistry, high-resolution observations of physical-biological interactions and greater observational capability in both the mesopelagic zone and harsh environments, such as the Arctic. We are now entering a new era for biological SOs, one in which our motivations have evolved from the need to acquire basic understanding of the ocean's state and variability, to a need to understand ocean biogeochemistry in the context of increasing pressure in the form of climate change, overfishing and eutrophication.
Collapse
|
12
|
Jones DOB, Yool A, Wei CL, Henson SA, Ruhl HA, Watson RA, Gehlen M. Global reductions in seafloor biomass in response to climate change. Glob Chang Biol 2014; 20:1861-72. [PMID: 24382828 PMCID: PMC4261893 DOI: 10.1111/gcb.12480] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 11/20/2013] [Indexed: 05/06/2023]
Abstract
Seafloor organisms are vital for healthy marine ecosystems, contributing to elemental cycling, benthic remineralization, and ultimately sequestration of carbon. Deep-sea life is primarily reliant on the export flux of particulate organic carbon from the surface ocean for food, but most ocean biogeochemistry models predict global decreases in export flux resulting from 21st century anthropogenically induced warming. Here we show that decadal-to-century scale changes in carbon export associated with climate change lead to an estimated 5.2% decrease in future (2091-2100) global open ocean benthic biomass under RCP8.5 (reduction of 5.2 Mt C) compared with contemporary conditions (2006-2015). Our projections use multi-model mean export flux estimates from eight fully coupled earth system models, which contributed to the Coupled Model Intercomparison Project Phase 5, that have been forced by high and low representative concentration pathways (RCP8.5 and 4.5, respectively). These export flux estimates are used in conjunction with published empirical relationships to predict changes in benthic biomass. The polar oceans and some upwelling areas may experience increases in benthic biomass, but most other regions show decreases, with up to 38% reductions in parts of the northeast Atlantic. Our analysis projects a future ocean with smaller sized infaunal benthos, potentially reducing energy transfer rates though benthic multicellular food webs. More than 80% of potential deep-water biodiversity hotspots known around the world, including canyons, seamounts, and cold-water coral reefs, are projected to experience negative changes in biomass. These major reductions in biomass may lead to widespread change in benthic ecosystems and the functions and services they provide.
Collapse
Affiliation(s)
- Daniel O B Jones
- National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, UK
| | | | | | | | | | | | | |
Collapse
|
13
|
Giering SLC, Sanders R, Lampitt RS, Anderson TR, Tamburini C, Boutrif M, Zubkov MV, Marsay CM, Henson SA, Saw K, Cook K, Mayor DJ. Reconciliation of the carbon budget in the ocean's twilight zone. Nature 2014; 507:480-3. [PMID: 24670767 DOI: 10.1038/nature13123] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 01/31/2014] [Indexed: 11/09/2022]
Abstract
Photosynthesis in the surface ocean produces approximately 100 gigatonnes of organic carbon per year, of which 5 to 15 per cent is exported to the deep ocean. The rate at which the sinking carbon is converted into carbon dioxide by heterotrophic organisms at depth is important in controlling oceanic carbon storage. It remains uncertain, however, to what extent surface ocean carbon supply meets the demand of water-column biota; the discrepancy between known carbon sources and sinks is as much as two orders of magnitude. Here we present field measurements, respiration rate estimates and a steady-state model that allow us to balance carbon sources and sinks to within observational uncertainties at the Porcupine Abyssal Plain site in the eastern North Atlantic Ocean. We find that prokaryotes are responsible for 70 to 92 per cent of the estimated remineralization in the twilight zone (depths of 50 to 1,000 metres) despite the fact that much of the organic carbon is exported in the form of large, fast-sinking particles accessible to larger zooplankton. We suggest that this occurs because zooplankton fragment and ingest half of the fast-sinking particles, of which more than 30 per cent may be released as suspended and slowly sinking matter, stimulating the deep-ocean microbial loop. The synergy between microbes and zooplankton in the twilight zone is important to our understanding of the processes controlling the oceanic carbon sink.
Collapse
Affiliation(s)
- Sarah L C Giering
- 1] National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK [2] Ocean and Earth Sciences, University of Southampton, European Way, Southampton SO14 3ZH, UK [3] Institute of Biological and Environmental Sciences, Oceanlab, University of Aberdeen, Newburgh AB41 6AA, UK
| | - Richard Sanders
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Richard S Lampitt
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Thomas R Anderson
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Christian Tamburini
- Aix-Marseille Université, Université de Toulon, CNRS/INSU, IRD, MIO, UM 110, 13288 Marseille Cedex 09, France
| | - Mehdi Boutrif
- Aix-Marseille Université, Université de Toulon, CNRS/INSU, IRD, MIO, UM 110, 13288 Marseille Cedex 09, France
| | - Mikhail V Zubkov
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Chris M Marsay
- 1] Ocean and Earth Sciences, University of Southampton, European Way, Southampton SO14 3ZH, UK [2] Department of Earth and Ocean Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Stephanie A Henson
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Kevin Saw
- National Oceanography Centre, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Kathryn Cook
- Marine Laboratory, Marine Scotland Science, Scottish Government, PO Box 101, 375 Victoria Road, Aberdeen AB11 9DB, UK
| | - Daniel J Mayor
- Institute of Biological and Environmental Sciences, Oceanlab, University of Aberdeen, Newburgh AB41 6AA, UK
| |
Collapse
|
14
|
|
15
|
|
16
|
Henson SA, Thomas AC. Phytoplankton scales of variability in the California Current System: 1. Interannual and cross-shelf variability. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jc004039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
17
|
Hemming VG, Prince GA, Rodriguez W, Kim HW, Brandt CD, Parrott RH, London WT, Fischer GW, Baron PA, Henson SA. Respiratory syncytial virus infections and intravenous gamma-globulins. Pediatr Infect Dis J 1988; 7:S103-6. [PMID: 3041354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The respiratory syncytial virus (RSV) is a common cause of bronchiolitis and pneumonia in infants and young children. Throughout the world annual RSV epidemics result in numerous hospitalizations, substantial morbidity and some mortality. Until the recent introduction of ribavirin only supportive therapy has been available for treating these infections. The development of animal models of RSV infection and the observation that some lots of immunoglobulin prepared for intravenous administration contained substantial RSV-neutralization antibody titers, prompted a series of studies examining the safety and efficacy of immunoglobulin prepared for intravenous administration in the prophylaxis and treatment of RSV infections. This discussion will review our published, or soon to be published, studies on the use of Sandoglobulin for both immunoprophylaxis and immunotherapy of RSV infections in cotton rats. It will summarize studies utilizing both parenteral and topical (tracheal) Sandoglobulin therapy for RSV infections in owl monkeys. Finally the results of a small double blind trial of parenteral albumin or Sandoglobulin in the therapy of RSV bronchiolitis and/or pneumonia in hospitalized children will be reviewed. The data show that immunoprophylaxis and immunotherapy of RSV infections in laboratory animals was well-tolerated, was safe and induced highly significant reductions in RSV shedding from the lower respiratory tract. Further, immunotherapy of RSV infections in children was also well-tolerated, induced no short or long term evidence of toxicity or injury and caused significant improvements in oxygenation and reductions in RSV shed from the respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- V G Hemming
- Department of Pediatrics, F. Edward Hebert College of Medicine, Uniformed Services University of Health Sciences, Bethesda, MD
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Olson TA, Ruymann FB, Cook BA, Burgess DP, Henson SA, Thomas PJ. Newborn polymorphonuclear leukocyte aggregation: a study of physical properties and ultrastructure using chemotactic peptides. Pediatr Res 1983; 17:993-7. [PMID: 6657330 DOI: 10.1203/00006450-198312000-00013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) and N-formyl-L-methionyl-L-phenylalanine (FMP) were used to investigate neutrophil (PMN) aggregation. Neutrophils were isolated from healthy adult volunteers and term newborn cord blood. Neutrophil aggregation was measured after the addition of FMLP and FMP. Adult PMN aggregation curves demonstrated initial aggregation with slow deaggregation. Newborn neutrophil aggregation curves showed slow aggregation with no deaggregation. These results were identical to the adult and newborn neutrophil aggregation curves produced by C5a. Newborn PMN aggregates examined by scanning electromicrography showed frequent, dense aggregates compared with fewer, less dense aggregates of adult PMNs. Adult and newborn PMN aggregates differed when compared by transmission electromicrographs (EM). Newborn PMNs were tightly bound with cell membrane projections; adult PMNs were loosely bound with no cell membrane projections. Cytochalasin-B pretreated adult and newborn PMN aggregates displayed close approximation of cell membranes with large numbers of cytoplasmic projections. Newborn neutrophils are irreversibly aggregated by FMLP and FMP whereas adult neutrophils display an aggregation-deaggregation reaction. EM studies suggest that this irreversible aggregation of untreated newborn neutrophils may differ from the irreversible aggregation of cytochalasin-B pretreated neutrophils.
Collapse
|