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Abstract
10Be has been measured in a 300 m long ice core from Greenland. After a general analysis of the 10Be data the potential and the limitations of 10Be records in ice to reconstruct solar variability are discussed. Special emphasis is given to periods of low solar activity (Maunder Minimum etc.). The ‘clock problem’ is addressed, also the question whether the Schwabe cycle maintains its phase. Finally the question of what 10Be can tell us about changes of the solar irradiance in the past is explored.
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2
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Abstract
The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24. ELECTRONIC SUPPLEMENTARY MATERIAL Supplementary material is available for this article at 10.1007/lrsp-2015-4.
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Affiliation(s)
- David H. Hathaway
- NASA Ames Research Center, Mail Stop: 258-5, Moffett Field, CA 94035 USA
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3
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Jiwen L, Starovoitova VN, Wells DP. Long-term variations in the surface air 7Be concentration and climatic changes. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2013; 116:42-47. [PMID: 23103574 DOI: 10.1016/j.jenvrad.2012.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/17/2012] [Accepted: 08/24/2012] [Indexed: 06/01/2023]
Abstract
We have used EML Surface Air Sampling Program (SASP) data to analyze the long-term trend in (7)Be surface concentration and address possible correlation between this long-term trend and climatic changes, namely changes in precipitation patterns and temperature. In this paper we present (7)Be concentration data from 23 sites, spanning over 25 years, all over the world, and extract long-term trend parameter using two independent techniques. The (7)Be concentrations in most stations show a pronounced decreasing trend, potentially corresponding to statistically significant changes in transporting (7)Be from upper atmosphere source to these sites. Weak negative correlation between (7)Be concentration and amount of precipitation was also observed. However, more data from more representative sites around the world are needed the statistical robustness of this trend.
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Affiliation(s)
- Liu Jiwen
- Idaho State University, Idaho Accelerator Center, 1500 Alvin Ricken Dr., Pocatello, ID 83201, USA
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4
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Mackay DH. The Sun's global magnetic field. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:3151-3168. [PMID: 22665897 DOI: 10.1098/rsta.2011.0536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Our present-day understanding of solar and stellar magnetic fields is discussed from both an observational and theoretical viewpoint. To begin with, observations of the Sun's large-scale magnetic field are described, along with recent advances in measuring the spatial distribution of magnetic fields on other stars. Following this, magnetic flux transport models used to simulate photospheric magnetic fields and the wide variety of techniques used to deduce global coronal magnetic fields are considered. The application and comparison of these models to the Sun's open flux, hemispheric pattern of solar filaments and coronal mass ejections are then discussed. Finally, recent developments in the construction of steady-state global magnetohydrodynamic models are considered, along with key areas of future research.
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Affiliation(s)
- Duncan H Mackay
- School of Mathematics and Statistics, University of St Andrews, Fife, UK.
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5
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Elmore D, Phillips FM. Accelerator mass spectrometry for measurement of long-lived radioisotopes. Science 2010; 236:543-50. [PMID: 17740475 DOI: 10.1126/science.236.4801.543] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.
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6
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Field CV, Schmidt GA, Shindell DT. Interpreting10Be changes during the Maunder Minimum. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010578] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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8
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Miyahara H, Masuda K, Muraki Y, Kitagawa H, Nakamura T. Variation of solar cyclicity during the Spoerer Minimum. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005ja011016] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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9
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McCracken KG. A phenomenological study of the long-term cosmic ray modulation, 850–1958 AD. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004ja010685] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Solar and climatic implications of the centennial and millennial periodicities in atmospheric Δ14C Variations. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/141gm17] [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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11
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Usoskin IG, Solanki SK, Schüssler M, Mursula K, Alanko K. Millennium-scale sunspot number reconstruction: evidence for an unusually active sun since the 1940s. PHYSICAL REVIEW LETTERS 2003; 91:211101. [PMID: 14683287 DOI: 10.1103/physrevlett.91.211101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2003] [Indexed: 05/21/2023]
Abstract
The extension of the sunspot number series backward in time is of considerable interest for dynamo theory, solar, stellar, and climate research. We have used records of the (10)Be concentration in polar ice to reconstruct the average sunspot activity level for the period between the year 850 to the present. Our method uses physical models for processes connecting the (10)Be concentration with the sunspot number. The reconstruction shows reliably that the period of high solar activity during the last 60 years is unique throughout the past 1150 years. This nearly triples the time interval for which such a statement could be made previously.
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Affiliation(s)
- Ilya G Usoskin
- Sodankylä Geophysical Observatory (Oulu unit), University of Oulu, FIN-90014 Oulu, Finland.
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12
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Peristykh AN. Persistence of the Gleissberg 88-year solar cycle over the last ∼12,000years: Evidence from cosmogenic isotopes. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002ja009390] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Grimm EC, Jacobson GL. Late-Quaternary vegetation history of the eastern United States. THE QUATERNARY PERIOD IN THE UNITED STATES 2003. [DOI: 10.1016/s1571-0866(03)01017-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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15
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Jöckel P. The seasonal cycle of cosmogenic14CO at the surface level: A solar cycle adjusted, zonal-average climatology based on observations. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jd001104] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Kromer B, Manning SW, Kuniholm PI, Newton MW, Spurk M, Levin I. Regional 14CO2 offsets in the troposphere: magnitude, mechanisms, and consequences. Science 2001; 294:2529-32. [PMID: 11743160 DOI: 10.1126/science.1066114] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Radiocarbon dating methods typically assume that there are no significant tropospheric (14)CO(2) gradients within the low- to mid-latitude zone of the Northern Hemisphere. Comparison of tree ring (14)C data from southern Germany and Anatolia supports this assumption in general but also documents episodes of significant short-term regional (14)CO(2) offsets. We suggest that the offset is caused by an enhanced seasonal (14)CO(2) cycle, with seasonally peaked flux of stratospheric (14)C into the troposphere during periods of low solar magnetic activity, coinciding with substantial atmospheric cooling. Short-term episodes of regional (14)CO(2) offsets are important to palaeoclimate studies and to high-resolution archaeological dating.
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Affiliation(s)
- B Kromer
- Heidelberger Akademie der Wissenschaften, Institut für Umweltphysik der Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany.
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17
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Bond G, Kromer B, Beer J, Muscheler R, Evans MN, Showers W, Hoffmann S, Lotti-Bond R, Hajdas I, Bonani G. Persistent solar influence on North Atlantic climate during the Holocene. Science 2001; 294:2130-6. [PMID: 11739949 DOI: 10.1126/science.1065680] [Citation(s) in RCA: 217] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Surface winds and surface ocean hydrography in the subpolar North Atlantic appear to have been influenced by variations in solar output through the entire Holocene. The evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon-14 and beryllium-10 and centennial to millennial time scale changes in proxies of drift ice measured in deep-sea sediment cores. A solar forcing mechanism therefore may underlie at least the Holocene segment of the North Atlantic's "1500-year" cycle. The surface hydrographic changes may have affected production of North Atlantic Deep Water, potentially providing an additional mechanism for amplifying the solar signals and transmitting them globally.
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Affiliation(s)
- G Bond
- Lamont-Doherty Earth Observatory of Columbia University, Route 9W, Palisades, NY 10964, USA.
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18
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McCracken KG, Dreschhoff GAM, Smart DF, Shea MA. Solar cosmic ray events for the period 1561-1994: 2. The Gleissberg periodicity. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000238] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Juckett DA. Period and phase comparisons of near-decadal oscillations in solar, geomagnetic, and cosmic ray time series. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Usoskin IG, Mursula K, Kovaltsov GA. Heliospheric modulation of cosmic rays and solar activity during the Maunder minimum. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000105] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Lockwood M. Long-term variations in the magnetic fields of the Sun and the heliosphere: Their origin, effects, and implications. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000ja000115] [Citation(s) in RCA: 72] [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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22
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The nature of the solar activity during the Maunder Minimum revealed by the Guliya ice core record. CHINESE SCIENCE BULLETIN-CHINESE 2000. [DOI: 10.1007/bf02886314] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Muscheler R, Beer J, Wagner G, Finkel RC. Changes in deep-water formation during the Younger Dryas event inferred from 10Be and 14C records. Nature 2000; 408:567-70. [PMID: 11117740 DOI: 10.1038/35046041] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Variations in atmospheric radiocarbon (14C) concentrations can be attributed either to changes in the carbon cycle--through the rate of radiocarbon removal from the atmosphere--or to variations in the production rate of 14C due to changes in solar activity or the Earth's magnetic field. The production rates of 10Be and 14C vary in the same way, but whereas atmospheric radiocarbon concentrations are additionally affected by the carbon cycle, 10Be concentrations reflect production rates more directly. A record of the 10Be production-rate variations can therefore be used to separate the two influences--production rates and the carbon cycle--on radiocarbon concentrations. Here we present such an analysis of the large fluctuations in atmospheric 14C concentrations, of unclear origin, that occurred during the Younger Dryas cold period. We use the 10Be record from the GISP2 ice core to model past production rates of radionuclides, and find that the largest part of the fluctuations in atmospheric radiocarbon concentrations can be attributed to variations in production rate. The residual difference between measured 14C concentrations and those modelled using the 10Be record can be explained with an additional change in the carbon cycle, most probably in the amount of deep-water formation.
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Affiliation(s)
- R Muscheler
- Department of Surface Waters, EAWAG, Dübendorf, Switzerland.
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24
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25
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Variations of Younger Dryas atmospheric radiocarbon explicable without ocean circulation changes. Nature 2000; 403:877-80. [PMID: 10706281 DOI: 10.1038/35002547] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The concentration of radiocarbon, 14C, in the atmosphere depends on its production rate by cosmic rays, and on the intensity of carbon exchange between the atmosphere and other reservoirs, for example the deep oceans. For the Holocene (the past approximately 11,500 years), it has been shown that fluctuations in atmospheric radiocarbon concentrations have been caused mostly by variations in the solar magnetic field. Recent progress in extending the radiocarbon record backwards in time has indicated especially high atmospheric radiocarbon concentrations in the Younger Dryas cold period, between 12,700 and 11,500 years before the present. These high concentrations have been interpreted as a result of a reduced exchange with the deep-ocean reservoir, caused by a drastic weakening of the deep-ocean ventilation. Here we present a high-resolution reconstruction of atmospheric radiocarbon concentrations, derived from annually laminated sediments of two Polish lakes, Lake Gosciaz and Lake Perespilno. These records indicate that the maximum in atmospheric radiocarbon concentrations in the early Younger Dryas was smaller than previously believed, and might have been caused by variations in solar activity. If so, there is no indication that the deep-ocean ventilation in the Younger Dryas was significantly different from today's.
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26
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27
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Kheshgi HS, Jain AK, Wuebbles DJ. Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and carbon isotope records. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jd900992] [Citation(s) in RCA: 19] [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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28
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Black DE, Peterson LC, Overpeck JT, Kaplan A, Evans MN, Kashgarian M. Eight centuries of north atlantic ocean atmosphere variability. Science 1999; 286:1709-13. [PMID: 10576732 DOI: 10.1126/science.286.5445.1709] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Climate in the tropical North Atlantic is controlled largely by variations in the strength of the trade winds, the position of the Intertropical Convergence Zone, and sea surface temperatures. A high-resolution study of Caribbean sediments provides a subdecadally resolved record of tropical upwelling and trade wind variability spanning the past 825 years. These results confirm the importance of a decadal (12- to 13-year) mode of Atlantic variability believed to be driven by coupled tropical ocean-atmosphere dynamics. Although a well-defined interdecadal mode of variability does not appear to be characteristic of the tropical Atlantic, there is evidence that century-scale variability is substantial. The tropical Atlantic may also have been involved in a major shift in Northern Hemisphere climate variability that took place about 700 years ago.
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Affiliation(s)
- DE Black
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA. National Oceanic and Atmospheric Administration Paleoclimatology Program and the Institute for Arctic and Alpine Research, University of Colorado, B
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29
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Finkel RC, Nishiizumi K. Beryllium 10 concentrations in the Greenland Ice Sheet Project 2 ice core from 3-40 ka. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jc01282] [Citation(s) in RCA: 216] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Tandem-accelerator mass-spectrometry measurements of
36
C1,
129
I and osmium isotopes in diverse natural samples. ACTA ACUST UNITED AC 1997. [DOI: 10.1098/rsta.1987.0076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Tandem AMS measurements at Rochester in the past few years have mainly involved the radioisotopes
36
Cl and
129
I, and some work on
10
Be, in a variety of terrestrial and extraterrestrial samples. Some m easurem ents have also been m ade on certain stable isotopes of osmium in meteorites and geological samples from impact craters. M easurem ents of
36
Cl have been made in groundwater and surface rocks for dating purposes, in ice and soil samples containing nuclear-weapon testing fallout for tracing water movement, and in meteorites and Antarctic ice for terrestrial and extraterrestrial meteoritic age determination. Also,
10
Be has been measured in a lake sediment, and
36
Cl in Greenland ice, through the period of the Maunder minimum ;
129
I has been measured in hydrological systems, in petroleum and in hydrothermal convection cells in the oceanic crust. Other applications involving measurements of these two radioisotopes include hydrotherm al fluids associated with gold mineralization and the determination of the integrity of possible sites for deep nuclear-waste disposal. Previously, the Rochester tandem was employed to measure
14
C and isotopes of platinum and iridium in natural samples.
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31
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Abstract
The power spectral density of the specific activity of radiocarbon variations, using an absolute chronology based on tree ring count, exhibits spectral lines at a number of periods: 2300, 964, 753, 717, 493, 413, 357, 229 and 208 years as well as recording a secular variation over the full 9000-year record. These variations appear in both the La Jolla and Belfast radiocarbon records and some are also detected in the Camp Century 10Be record, though its secular variation appears to lead that of the radiocarbon by about 2100 years. Of the total number of nine prominent radiocarbon features, most are mutually dependent with perhaps only three independent lines. The 208-year period appears modulated by the long 2300-year period. The evidence of modulation of the 208- (and possibly 229-) year period (s) by the 2300-year period suggests a solar source for the latter features, through 200-year spectral features are also detected in the tree ring spectrum, thus tying Sun and climate together. A solar source signalled jointly through correlated radiocarbon and atmospheric temperature variations suggests that solar hydromagnetic and bolometric variations are coupled. Moreover, as evidence is lacking for variations in 10Be or in the geomagnetic field with a period of 2300 years, by a process of elimination together with suggestive global ocean deep water return times of more or less a millennium, a surmise is that chemical resonances may account for the periodicity in radiocarbon with the variation in oceanic carbonate concentration recorded in the radiocarbon record as tracer. The evidence for correlated oscillations in air temperature detected by tree-ring-growth cyclicity in Campito Mt bristlecone pine trees and the radiocarbon variability is consistent with a model of atmosphere-ocean resonances underlying the radiocarbon periodicities.
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32
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Abstract
Evidence from the advances and retreats of alpine glaciers during the Holocene suggests that there were at least 14 century-timescale cool periods similar to the recent Little Ice Age. Here, we examine the hypothesis that these cool periods were caused by reductions in solar irradiance. A statistically significant correlation is found between the global glacial advance and retreat chronology of Röthlisberger and variations in atmospheric
14
C concentration. A simple energy-balance climate model is used to show that the mean reduction of solar irradiance during times of maximum
14
C anomaly like the Maunder Minimum would have to have been between 0.22 and 0.55 % to have caused these cool periods. If a similar solar irradiance perturbation began early in the 21st century, the associated climate effects would be noticeable, but still considerably less than those expected to result from future greenhouse gas concentration increases.
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33
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Bonino G. Record of galactic-cosmic-ray variations in terrestrial archives and meteorites. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf02508126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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Nishiizumi K, Finkel RC, Klein J, Kohl CP. Cosmogenic production of7Be and10Be in water targets. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb02270] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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35
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Voss H, Kurths J, Schwarz U. Reconstruction of grand minima of solar activity from Δ14C data: Linear and nonlinear signal analysis. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96ja00542] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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36
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Bonino G, Cini Castagnoli G, Taricco C, Bhandari N. Century scale solar variability imprinted in the 44Ti activity in meteorites. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 1996; 17:127-130. [PMID: 11540359 DOI: 10.1016/0273-1177(95)00523-h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The measurements of gamma-activity of the 44Ti (T1/2 = 66.6 years) produced by spallation reaction of galactic cosmic rays (GCR) in Alfianello, Olivenza, Rio Negro, Dhajala and Torino meteorites, which fell in the time interval 1883 AD (Alfianello)-1988 AD (Torino), show a century scale modulation, connected to long-term solar-wind flux variations in the interplanetary space. The variation of the 44Ti activity with the time of fall of meteorites is qualitatively consistent with the Gleissberg solar cycle, but the amplitude is three-four times higher than expected (about 5%) for GCR flux modulated by solar activity, as determined solely by the sunspot number. The cosmogenic 44Ti is a suitable radioisotope for this investigation, but its activity in meteorites is very low. We performed these measurements in the underground low level counting station of Monte dei Cappuccini in Torino, by means of a big hyperpure Ge crystal (approximately 2 kg) in selective coincidence with a heavy NaI (T1) scintillation detector (approximately 28 kg). This system allows a reliable and non destructive measurement of 44Ti (44Sc) in meteorites of 200-1200 g in weight. The background is about 1 count per day in the gamma-peak at 1157 keV of 44Sc in equilibrium with its parent 44Ti. The high stability of the performance allows long-lasting runs (approximately 10(7) s) in order to attain results with a standard deviation up to about 10%.
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Affiliation(s)
- G Bonino
- Istituto di Fisica Generale-Universita, Torino, Italy
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38
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O'Brien K, Friedberg W, Sauer HH, Smart DF. Atmospheric cosmic rays and solar energetic particles at aircraft altitudes. ENVIRONMENT INTERNATIONAL 1996; 22 Suppl 1:S9-S44. [PMID: 11542509 DOI: 10.1016/s0160-4120(96)00086-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Galactic cosmic rays, which are thought to be produced and accelerated by a variety of mechanisms in the Milky Way galaxy, interact with the solar wind, the earth's magnetic field, and its atmosphere to produce hadron, lepton, and photon fields at aircraft altitudes that are quite unlike anything produced in the laboratory. The energy spectra of these secondary particles extend from the lowest possible energy to energies over an EeV. In addition to cosmic rays, energetic particles, generated on the sun by solar flares or coronal mass ejections, bombard the earth from time to time. These particles, while less energetic than cosmic rays, also produce radiation fields at aircraft altitudes which have qualitatively the same properties as cosmic rays. The authors have calculated atmospheric cosmic-ray angular fluxes, spectra, scalar fluxes, and ionization, and compared them with experimental data. Agreement with these data is seen to be good. These data have been used to calculate equivalent doses in a simplified human phantom at aircraft altitudes and the estimated health risks to aircraft crews. The authors have also calculated the radiation doses from several large solar energetic particle events (known as GLEs, or Ground Level Events), which took place in 1989, including the very large event known as GLE 42, which took place on September 29th and 30th of that year. The spectra incident on the atmosphere were determined assuming diffusive shock theory. Unfortunately, there are essentially no experimental data with which to compare these calculations.
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Affiliation(s)
- K O'Brien
- Northern Arizona University, Flagstaff 86011, USA
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39
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Bonino G, Castagnoli GC, Bhandari N, Taricco C. Behavior of the Heliosphere over Prolonged Solar Quiet Periods by
44
Ti Measurements in Meteorites. Science 1995. [DOI: 10.1126/science.270.5242.1648] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- G. Bonino
- G. Bonino, G. Cini Castagnoli, C. Taricco, Istituto di Cosmogeofisica, Corso Fiume 4, 10133 Torino, Italy, and Istituto di Fisica Generale dell'Universita', Via Giuria 1, 10125 Torino, Italy
| | - G. Cini Castagnoli
- G. Bonino, G. Cini Castagnoli, C. Taricco, Istituto di Cosmogeofisica, Corso Fiume 4, 10133 Torino, Italy, and Istituto di Fisica Generale dell'Universita', Via Giuria 1, 10125 Torino, Italy
| | - N. Bhandari
- N. Bhandari, Physical Research Laboratory, Ahmedabad 380009, India
| | - C. Taricco
- G. Bonino, G. Cini Castagnoli, C. Taricco, Istituto di Cosmogeofisica, Corso Fiume 4, 10133 Torino, Italy, and Istituto di Fisica Generale dell'Universita', Via Giuria 1, 10125 Torino, Italy
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Abstract
Schizophrenia, a disorder with a high, fairly uniform, global distribution, can occur with or without an accompanying family history of mental disorder. Given the preponderance of sporadic cases and the low fertility of genetic cases, this combination suggests that the disorder might be caused by a globally active teratogen. It has recently been shown that some factor associated with high sunspot activity acts transgenerationally to reduce lifespan. The following article discusses the relevance of that finding to changes in the incidence of schizophrenia and suggests that schizophrenia is caused by some factor associated with sunspots.
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Shaffer G, Sarmiento JL. Biogeochemical cycling in the global ocean: 1. A new, analytical model with continuous vertical resolution and high-latitude dynamics. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/94jc01167] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Druffel ERM, Griffin S. Large variations of surface ocean radiocarbon: Evidence of circulation changes in the southwestern Pacific. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/93jc02113] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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ARNOLD JR, LAL D. The Significance of the Contributions of S. A. Korff to the Field of Cosmogenic Nuclides. Ann N Y Acad Sci 1992. [DOI: 10.1111/j.1749-6632.1992.tb17065.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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45
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Walker JC, Kasting JF. Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide. GLOBAL AND PLANETARY CHANGE 1992. [PMID: 11537854 DOI: 10.1016/0031-0182(92)90207-l] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the formulation of the rock cycle and to the dissolution of deep sea carbonate sediments. Atmospheric carbon dioxide continues to increase as long fossil fuel is burned at a significant rate, because the rate of fossil fuel production of carbon dioxide far exceeds the rates at which geochemical processes can remove carbon dioxide from the atmosphere. The maximum concentration of carbon dioxide achieved in the atmosphere depends on the total amount of fossil fuel burned, but only weakly on the rate of burning. The future course of atmospheric carbon dioxide is, however, very sensitive to the fate of the forests in this simulation because of the important role assigned to carbon dioxide fertilization of plant growth rate. Forest clearance drives up atmospheric carbon dioxide not only by converting biomass into atmospheric carbon dioxide but more importantly by reducing the capacity of the biota to sequester fossil fuel carbon dioxide. In this simulation, atmospheric carbon dioxide levels could be sustained indefinitely below 500 parts per million (ppm) if fossil fuel combustion rates were immediately cut from their present value of 5 x 10(14) m/y to 0.2 x 10(14) m/y (a factor of 25 reduction) and if further forest clearance were halted. If neither of these conditions is met and if we consume most of the world's fossil fuel reserves, peak carbon dioxide concentrations of 1000-2000 ppm are probable within the next few centuries.
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Affiliation(s)
- J C Walker
- Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor 48109
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46
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Beer J, Blinov A, Bonani G, Finkel RC, Hofmann HJ, Lehmann B, Oeschger H, Sigg A, Schwander J, Staffelbach T, Stauffer B, Suter M, Wötfli W. Use of 10Be in polar ice to trace the 11-year cycle of solar activity. Nature 1990. [DOI: 10.1038/347164a0] [Citation(s) in RCA: 293] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bard E, Hamelin B, Fairbanks RG, Zindler A. Calibration of the 14C timescale over the past 30,000 years using mass spectrometric U–Th ages from Barbados corals. Nature 1990. [DOI: 10.1038/345405a0] [Citation(s) in RCA: 1070] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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49
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Stuiver M. Global Warming Report. Science 1990. [DOI: 10.1126/science.247.4938.15.b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Minze Stuiver
- Department of Geological Sciences and Quarternary Research Center, University of Washington, AK60, Seattle, WA 98195
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50
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Stuiver M. Global Warming Report. Science 1990. [DOI: 10.1126/science.247.4938.15-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Minze Stuiver
- Department of Geological Sciences and Quarternary Research Center, University of Washington, AK60, Seattle, WA 98195
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