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Yan Y, Brook EJ, Kurbatov AV, Severinghaus JP, Higgins JA. Ice core evidence for atmospheric oxygen decline since the Mid-Pleistocene transition. SCIENCE ADVANCES 2021; 7:eabj9341. [PMID: 34910502 PMCID: PMC8673763 DOI: 10.1126/sciadv.abj9341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
The history of atmospheric oxygen (PO2) and the processes that act to regulate it remain enigmatic because of difficulties in quantitative reconstructions using indirect proxies. Here, we extend the ice-core record of PO2 using 1.5-million-year-old (Ma) discontinuous ice samples drilled from Allan Hills Blue Ice Area, East Antarctica. No statistically significant difference exists in PO2 between samples at 1.5 Ma and 810 thousand years (ka), suggesting that the Late-Pleistocene imbalance in O2 sources and sinks began around the time of the transition from 40- to 100-ka glacial cycles in the Mid-Pleistocene between ~1.2 Ma and 700 ka. The absence of a coeval secular increase in atmospheric CO2 over the past ~1 Ma requires negative feedback mechanisms such as Pco2-dependent silicate weathering. Fast processes must also act to suppress the immediate Pco2 increase because of the imbalance in O2 sinks over sources beginning in the Mid-Pleistocene.
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Affiliation(s)
- Yuzhen Yan
- Department of Geosciences, Princeton University, Princeton, NJ, USA
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX, USA
| | - Edward J. Brook
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
| | | | | | - John A. Higgins
- Department of Geosciences, Princeton University, Princeton, NJ, USA
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Abstract
Dissolved gases produce a gas pressure. This gas pressure is the appropriate physical quantity for judging the possibility of bubble formation and hence it is central for understanding exchange of climate-relevant gases between (limnic) water and the atmosphere. The contribution of ebullition has widely been neglected in numerical simulations. We present measurements from six lacustrine waterbodies in Central Germany: including a natural lake, a drinking water reservoir, a mine pit lake, a sand excavation lake, a flooded quarry, and a small flooded lignite opencast, which has been heavily polluted. Seasonal changes of oxygen and temperature are complemented by numerical simulations of nitrogen and calculations of vapor pressure to quantify the contributions and their dynamics in lacustrine waters. In addition, accumulation of gases in monimolimnetic waters is demonstrated. We sum the partial pressures of the gases to yield a quantitative value for total gas pressure to reason which processes can force ebullition at which locations. In conclusion, only a small number of gases contribute decisively to gas pressure and hence can be crucial for bubble formation.
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Hamme RC, Nicholson DP, Jenkins WJ, Emerson SR. Using Noble Gases to Assess the Ocean's Carbon Pumps. ANNUAL REVIEW OF MARINE SCIENCE 2019; 11:75-103. [PMID: 30216737 DOI: 10.1146/annurev-marine-121916-063604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Natural mechanisms in the ocean, both physical and biological, concentrate carbon in the deep ocean, resulting in lower atmospheric carbon dioxide. The signals of these carbon pumps overlap to create the observed carbon distribution in the ocean, making the individual impact of each pump difficult to disentangle. Noble gases have the potential to directly quantify the physical carbon solubility pump and to indirectly improve estimates of the biological organic carbon pump. Noble gases are biologically inert, can be precisely measured, and span a range of physical properties. We present dissolved neon, argon, and krypton data spanning the Atlantic, Southern, Pacific, and Arctic Oceans. Comparisons between deep-ocean observations and models of varying complexity enable the rates of processes that control the carbon solubility pump to be quantified and thus provide an important metric for ocean model skill. Noble gases also provide a powerful means of assessing air-sea gas exchange parameterizations.
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Affiliation(s)
- Roberta C Hamme
- School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada;
| | - David P Nicholson
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, USA; ,
| | - William J Jenkins
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02540, USA; ,
| | - Steven R Emerson
- School of Oceanography, University of Washington, Seattle, Washington 98195, USA;
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Goldman JAL, Bender ML, Morel FMM. The effects of pH and pCO 2 on photosynthesis and respiration in the diatom Thalassiosira weissflogii. PHOTOSYNTHESIS RESEARCH 2017; 132:83-93. [PMID: 28062941 DOI: 10.1007/s11120-016-0330-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/20/2016] [Indexed: 06/06/2023]
Abstract
The response of marine phytoplankton to the ongoing increase in atmospheric pCO2 reflects the consequences of both increased CO2 concentration and decreased pH in surface seawater. In the model diatom Thalassiosira weissflogii, we explored the effects of varying pCO2 and pH, independently and in concert, on photosynthesis and respiration by incubating samples in water enriched in H218O. In long-term experiments (~6-h) at saturating light intensity, we observed no effects of pH or pCO2 on growth rate, photosynthesis or respiration. This absence of a measurable response reflects the very small change in energy used by the carbon concentrating mechanism (CCM) compared to the energy used in carbon fixation. In short-term experiments (~3 min), we also observed no effects of pCO2 or pH, even under limiting light intensity. We surmise that in T. weissflogii, it is the photosynthetic production of NADPH and ATP, rather than the CO2-saturation of Rubisco that controls the rate of photosynthesis at low irradiance. In short-term experiments, we observed a slightly higher respiration rate at low pH at the onset of the dark period, possibly reflecting the energy used for exporting H+ and maintaining pH homeostasis. Based on what is known of the biochemistry of marine phytoplankton, our results are likely generalizable to other diatoms and a number of other eukaryotic species. The direct effects of ocean acidification on growth, photosynthesis and respiration in these organisms should be small over the range of atmospheric pCO2 predicted for the twenty-first century.
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Affiliation(s)
- Johanna A L Goldman
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA.
- Center for Environmental Genomics, School of Oceanography, University of Washington, Seattle, WA, 98105, USA.
| | - Michael L Bender
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
| | - François M M Morel
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
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Reconstructing the last interglacial at Summit, Greenland: Insights from GISP2. Proc Natl Acad Sci U S A 2016; 113:9710-5. [PMID: 27528680 DOI: 10.1073/pnas.1524766113] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Eemian (last interglacial, 130-115 ka) was likely the warmest of all interglacials of the last 800 ka, with summer Arctic temperatures 3-5 °C above present. Here, we present improved Eemian climate records from central Greenland, reconstructed from the base of the Greenland Ice Sheet Project 2 (GISP2) ice core. Our record comes from clean, stratigraphically disturbed, and isotopically warm ice from 2,750 to 3,040 m depth. The age of this ice is constrained by measuring CH4 and δ(18)O of O2, and comparing with the historical record of these properties from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores. The δ(18)Oice, δ(15)N of N2, and total air content for samples dating discontinuously from 128 to 115 ka indicate a warming of ∼6 °C between 127-121 ka, and a similar elevation history between GISP2 and NEEM. The reconstructed climate and elevation histories are compared with an ensemble of coupled climate-ice-sheet model simulations of the Greenland ice sheet. Those most consistent with the reconstructed temperatures indicate that the Greenland ice sheet contributed 5.1 m (4.1-6.2 m, 95% credible interval) to global eustatic sea level toward the end of the Eemian. Greenland likely did not contribute to anomalously high sea levels at ∼127 ka, or to a rapid jump in sea level at ∼120 ka. However, several unexplained discrepancies remain between the inferred and simulated histories of temperature and accumulation rate at GISP2 and NEEM, as well as between the climatic reconstructions themselves.
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Young JN, Goldman JAL, Kranz SA, Tortell PD, Morel FMM. Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms. THE NEW PHYTOLOGIST 2015; 205:172-81. [PMID: 25283055 DOI: 10.1111/nph.13021] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/27/2014] [Indexed: 05/19/2023]
Abstract
High-latitude oceans are areas of high primary production despite temperatures that are often well below the thermal optima of enzymes, including the key Calvin Cycle enzyme, Ribulose 1,5 bisphosphate carboxylase oxygenase (Rubisco). We measured carbon fixation rates, protein content and Rubisco abundance and catalytic rates during an intense diatom bloom in the Western Antarctic Peninsula (WAP) and in laboratory cultures of a psychrophilic diatom (Fragilariopsis cylindrus). At -1°C, the Rubisco turnover rate, kcat (c) , was 0.4 C s(-1) per site and the half saturation constant for CO2 was 15 μM (vs c. 3 C s(-1) per site and 50 μM at 20°C). To achieve high carboxylation rates, psychrophilic diatoms increased Rubisco abundance to c. 8% of biomass (vs c. 0.6% at 20°C), along with their total protein content, resulting in a low carbon : nitrogen ratio of c. 5. In psychrophilic diatoms, Rubisco must be almost fully active and near CO2 saturation to achieve carbon fixation rates observed in the WAP. Correspondingly, total protein concentrations were close to the highest ever measured in phytoplankton and likely near the maximum possible. We hypothesize that this high protein concentration, like that of Rubisco, is necessitated by slow enzyme rates, and that carbon fixation rates in the WAP are near a theoretical maximum.
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Affiliation(s)
- Jodi N Young
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
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Goldman JAL, Kranz SA, Young JN, Tortell PD, Stanley RHR, Bender ML, Morel FMM. Gross and net production during the spring bloom along the Western Antarctic Peninsula. THE NEW PHYTOLOGIST 2015; 205:182-191. [PMID: 25382393 DOI: 10.1111/nph.13125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/15/2014] [Indexed: 06/04/2023]
Abstract
This study explores some of the physiological mechanisms responsible for high productivity near the shelf in the Western Antarctic Peninsula despite a short growing season and cold temperature. We measured gross and net primary production at Palmer Station during the summer of 2012/2013 via three different techniques: incubation with H2 (18) O; incubation with (14) CO2 ; and in situ measurements of O2 /Ar and triple oxygen isotope. Additional laboratory experiments were performed with the psychrophilic diatom Fragilariopsis cylindrus. During the spring bloom, which accounted for more than half of the seasonal gross production at Palmer Station, the ratio of net-to-gross production reached a maximum greater than c. 60%, among the highest ever reported. The use of multiple techniques showed that these high ratios resulted from low heterotrophic respiration and very low daylight autotrophic respiration. Laboratory experiments revealed a similar ratio of net-to-gross O2 production in F. cylindrus and provided the first experimental evidence for an important level of cyclic electron flow (CEF) in this organism. The low ratio of community respiration to gross primary production observed during the bloom at Palmer Station may be characteristic of high latitude coastal ecosystems and partially supported by a very active CEF in psychrophilic phytoplankton.
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Ito T, Hamme RC, Emerson S. Temporal and spatial variability of noble gas tracers in the North Pacific. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006828] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Decrease in the autotrophic-to-heterotrophic biomass ratio of picoplankton in oligotrophic marine waters due to bottle enclosure. Appl Environ Microbiol 2011; 77:5739-46. [PMID: 21742930 DOI: 10.1128/aem.00066-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the effects of bottle enclosure on autotrophic and heterotrophic picoplankton in North and South subtropical Atlantic oligotrophic waters, where the biomass and metabolism of the microbial community are dominated by the picoplankton size class. We measured changes in both autotrophic (Prochlorococcus, Synechococcus, and picoeukaryotes) and heterotrophic picoplankton biomass during three time series experiments and in 16 endpoint experiments over 24 h in light and dark treatments. Our results showed a divergent effect of bottle incubation on the autotrophic and heterotrophic components of the picoplankton community. The biomass of picophytoplankton showed, on average, a >50% decrease, mostly affecting the picoeukaryotes and, to a lesser extent, Prochlorococcus. In contrast, the biomass of heterotrophic bacteria remained constant or increased during the incubations. We also sampled 10 stations during a Lagrangian study in the North Atlantic subtropical gyre, which enabled us to compare the observed changes in the auto- to heterotrophic picoplankton biomass ratio (AB:HB ratio) inside the incubation bottles with those taking place in situ. While the AB:HB ratio in situ remained fairly constant during the Lagrangian study, it decreased significantly during the 24 h of incubation experiments. Thus, the rapid biomass changes observed in the incubations are artifacts resulting from bottle confinement and do not take place in natural conditions. Our results suggest that short (<1 day) bottle incubations in oligotrophic waters may lead to biased estimates of the microbial metabolic balance by underestimating primary production and/or overestimating bacterial respiration.
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Chavez FP, Messié M, Pennington JT. Marine primary production in relation to climate variability and change. ANNUAL REVIEW OF MARINE SCIENCE 2011; 3:227-260. [PMID: 21329205 DOI: 10.1146/annurev.marine.010908.163917] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Marine photosynthetic plankton are responsible for approximately 50 petagrams (10(15)) of carbon per year of net primary production, an amount equivalent to that on land. This primary production supports essentially all life in the oceans and profoundly affects global biogeochemical cycles and climate. This review discusses the general distribution of primary production in the sea, the processes that regulate this distribution, and how marine primary production is sensitive to climate variability and change. Statistical modes of ocean variability and their characteristic interannual to multi-decadal timescales over the last century are described. Recent in situ and satellite time-series of primary production can be clearly linked to interannual ocean variability. Global marine primary production appears to have increased over the past several decades in association with multi-decadal variations. A paleoclimate record extends discussion to the centennial scale, providing contrasting insights into how marine primary production might vary in the future.
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Affiliation(s)
- Francisco P Chavez
- Monterey Bay Aquarium Research Institute, Moss Landing, California 95039, USA.
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Abstract
Knowledge of the outgassing history of radiogenic (40)Ar, derived over geologic time from the radioactive decay of (40)K, contributes to our understanding of the geodynamic history of the planet and the origin of volatiles on Earth's surface. The (40)Ar inventory of the atmosphere equals total (40)Ar outgassing during Earth history. Here, we report the current rate of (40)Ar outgassing, accessed by measuring the Ar isotope composition of trapped gases in samples of the Vostok and Dome C deep ice cores dating back to almost 800 ka. The modern outgassing rate (1.1 +/- 0.1 x 10(8) mol/yr) is in the range of values expected by summing outgassing from the continental crust and the upper mantle, as estimated from simple calculations and models. The measured outgassing rate is also of interest because it allows dating of air trapped in ancient ice core samples of unknown age, although uncertainties are large (+/-180 kyr for a single sample or +/-11% of the calculated age, whichever is greater).
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Deutsch C, Emerson S, Thompson L. Physical-biological interactions in North Pacific oxygen variability. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jc003179] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hendricks MB, Bender ML, Barnett BA, Strutton P, Chavez FP. Triple oxygen isotope composition of dissolved O2in the equatorial Pacific: A tracer of mixing, production, and respiration. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jc002735] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Russ ME. Temporal and spatial variations in R:P ratios in Lake Superior, an oligotrophic freshwater environment. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jc001890] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Affiliation(s)
- David M Karl
- Department of Oceanography, University of Hawaii, Honolulu, Hawaii 96822, USA.
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Barkan E, Luz B. High-precision measurements of 17O/16O and 18O/16O of O2 and O2/Ar ratio in air. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:2809-2814. [PMID: 14673831 DOI: 10.1002/rcm.1267] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A method for high-precision and high-accuracy mass spectrometric measurements of the ratios among the three oxygen isotopes, and of the O(2)/Ar ratio, is presented. It involves separation of the O(2)-Ar mixture from air and includes a fully automated system that ensures highly reliable sample processing. Repeated measurements of atmospheric oxygen yield the repeatability (+/-SE x t, standard error of the mean (n = 12) multiplied by Student's t-factor for a 95% confidence limit) of 0.004, 0.003 and 0.2 per thousand for delta(18)O, delta(17)O and delta O(2)/Ar, respectively.
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Affiliation(s)
- Eugeni Barkan
- The Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Mechanisms of nitrous oxide production in the subtropical North Pacific based on determinations of the isotopic abundances of nitrous oxide and di-oxygen. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1465-9972(00)00031-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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The Oceans. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0074-6142(00)80116-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Christian JR, Lewis MR, Karl DM. Vertical fluxes of carbon, nitrogen, and phosphorus in the North Pacific Subtropical Gyre near Hawaii. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jc00369] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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