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Author Stephens, B.B.; Gurney, K.R.; Tans, P.P.; Sweeney, C.; Peters, W.; Bruhwiler, L.; Ciais, P.; Ramonet, M.; Bousquet, P.; Nakazawa, T.; Aoki, S.; Machida, T.; Inoue, G.; Vinnichenko, N.; Lloyd, J.; Jordan, A.; Heimann, M.; Shibistova, O.; Langenfelds, R.L.; Steele, L.P.; Francey, R.J.; Denning, A.S.
Title Weak Northern and Strong Tropical Land Carbon Uptake from Vertical Profiles of Atmospheric CO2 Type Journal Article
Year 2007 Publication Science Abbreviated Journal Science
Volume 316 Issue 5832 Pages 1732-1735
Keywords
Abstract Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of -1.5 petagrams of carbon per year (Pg C year-1) and weaker tropical emission of +0.1 Pg C year-1 compared with previous consensus estimates of -2.4 and +1.8 Pg C year-1, respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.
Programme 416
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8075 ISBN Medium
Area Expedition Conference
Notes 10.1126/science.1137004 Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5525
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Author Francia, P.; Lanzerotti, L.J.; Villante, U.; Lepidi, S.; Di Memmo, D.
Title A statistical analysis of low-frequency magnetic pulsations at cusp and cap latitudes in Antarctica Type Journal Article
Year 2005 Publication Journal of geophysical research-atmospheres Abbreviated Journal J. Geophys. Res.
Volume 110 Issue Pages
Keywords polar cap and cusp pulsations; magnetospheric wave guide modes; field line resonances; open/closed field line boundary; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions; 2740 Magnetospheric Physics: Magnetospheric configuration and dynamics; 2776 Magnetospheric Physics: Polar cap phenomena; 2706 Magnetospheric Physics: Cusp; 2752 Magnetospheric Physics: MHD waves and instabilities
Abstract We report a statistical analysis of low-frequency magnetic variations (magnetic pulsations, 0.8–7 mHz) at South Pole (74°S corrected geomagnetic latitude) and Terra Nova Bay (80°S) during 1996. The results show that at South Pole (at cusp latitudes) the pulsation power exhibits two maxima during the day, one in the local premidnight and the other in the morning. The first maximum disappears when the analysis is restricted to northward interplanetary magnetic field conditions (B z > 1 nT), suggesting that it might be associated to substorm phenomena. During closed magnetospheric conditions, when the cusp is expected to be located poleward with respect to the station, the spectral and polarization characteristics of pulsations between 1 and 3 mHz suggest that resonant oscillations of the outermost closed field lines commonly occur at South Pole in the local morning. At Terra Nova Bay, in the polar cap, the pulsation power is much lower and its diurnal variation is characterized by a single maximum, which occurs around local noon, when the station approaches the cusp. The corresponding polarization pattern indicates that Terra Nova Bay is always located poleward with respect to resonant field lines.
Programme 1130
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Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0148-0227 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5495
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Author Ciais, P.; Manning, A.C.; Reichstein, M.; Zaehle, S.; Bopp, L.
Title Nitrification amplifies the decreasing trends of atmospheric oxygen and implies a larger land carbon uptake Type Journal Article
Year 2007 Publication Global biogeochemical cycles Abbreviated Journal
Volume 21 Issue Pages
Keywords carbon cycle; nitrogen cycle; oxygen; 0330 Atmospheric Composition and Structure: Geochemical cycles
Abstract Atmospheric O2 trend measurements are used to partition global oceanic and land biotic carbon sinks on a multiannual basis. The underlying principle is that a terrestrial uptake or release of CO2 is accompanied by an opposite flux of O2. The molar ratio of the CO2 and O2 terrestrial fluxes should be 1, if no other elements are considered. However, reactive nitrogen produced by human activities (e.g., fertilizers, N deposition) is also being incorporated into plant tissues. The various reaction pathways of the terrestrial nitrogen cycle cause fluxes of atmospheric O2. Thus the cycles of nitrogen, carbon, and oxygen must be linked together. We report here on previously unconsidered anthropogenic nitrogen-related mechanisms which impact atmospheric O2 trends and thus the derived global carbon sinks. In particular, we speculate that anthropogenic-driven changes are driving the global nitrogen cycle to a more oxidized state, primarily through nitrification, nitrate fertilizer industrial production, and combustion of fossil fuels and anthropogenic biomass burning. The sum of these nitrogen-related processes acts to additionally decrease atmospheric O2 and slightly increase atmospheric CO2. We have calculated that the effective land biotic O2:CO2 molar ratio ranges between 0.76 and 1.04 rather than 1.10 (moles of O2 produced per mole of CO2 consumed) over the period 1993–2003, depending on which of four contrasting nitrogen oxidation and reduction pathway scenarios is used. Using the scenario in which we have most confidence, this implies a 0.23 PgC yr?1 correction to the global land biotic and oceanic carbon sinks of most recently reported estimates over 1993–2003, with the land biotic sink becoming larger and the oceanic sink smaller. We have attributed large uncertainties of 100% to all nitrogen-related O2 and CO2 fluxes and this corresponds up to ±0.09 PgC yr?1 increase in global carbon sink uncertainties. Thus accounting for anthropogenic nitrogen-related terrestrial fluxes of O2 results in a 45% larger land biotic sink of 0.74 ± 0.78 PgC yr?1 and a slightly smaller oceanic sink of 2.01 ± 0.66 PgC yr?1 for the decade 1993–2003.
Programme 439
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Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0886-6236 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5515
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Author Chulliat, A.; Blanter, E.; Le Mouël, J.-L.; Shnirman, M.
Title On the seasonal asymmetry of the diurnal and semidiurnal geomagnetic variations Type Journal Article
Year 2005 Publication Journal of geophysical research-atmospheres Abbreviated Journal J. Geophys. Res.
Volume 110 Issue Pages
Keywords daily variation; lower thermospheric winds; ionospheric dynamo; current system; geomagnetic activity; equinoxes; 1555 Geomagnetism and Paleomagnetism: Time variations: diurnal to decadal; 2437 Ionosphere: Ionospheric dynamics; 3369 Atmospheric Processes: Thermospheric dynamics; 3389 Atmospheric Processes: Tides and planetary waves
Abstract The diurnal and semidiurnal variations of the geomagnetic field are investigated at 18 observatories using long series of hourly values (up to 97 years at Sitka). The seasonal variations of amplitude of the 12-hour and 24-hour lines are obtained for the H and Z components using a 28-day sliding window. The Fourier analysis is performed using either all days within the window or only the five quietest days. At midlatitudes a strong lack of symmetry about the summer solstice is observed for both lines and both components. This effect is enhanced when selecting quiet days. When averaged over the entire series, the sign of this seasonal asymmetry is the same at 9 out of 10 midlatitude observatories for both lines and for a given component; it is opposite for the H and Z components. Such a coherent seasonal asymmetry is not found at low and high latitudes. At high latitudes a strong annual variation is found inside the polar caps, while a strong semiannual variation is found in the auroral zones. When selecting quiet days, these two effects are weaker, and the seasonal asymmetry becomes comparable to that at midlatitudes. At all latitudes the year-to-year variations of the seasonal asymmetry are uncorrelated with solar activity. It is suggested that lower thermospheric winds may have a similar seasonal asymmetry between spring and autumn equinoxes. Such an asymmetry is present in the published literature but has been overlooked. Possible causes for this wind asymmetry are reviewed.
Programme 139
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Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0148-0227 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5485
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Author Courtillot, V.; Le Mouël, J.-L.
Title The study of Earth's magnetism (1269–1950): A foundation by Peregrinus and subsequent development of geomagnetism and paleomagnetism Type Journal Article
Year 2007 Publication Reviews of geophysics Abbreviated Journal
Volume 45 Issue Pages
Keywords history; geomagnetism; paleomagnetism; 1599 Geomagnetism and Paleomagnetism: General or miscellaneous; 1714 History of Geophysics: Geomagnetism and paleomagnetism; 5440 Planetary Sciences: Solid Surface Planets: Magnetic fields and magnetism; 7999 Space Weather: General or miscellaneous; 9820 General or Miscellaneous: Techniques applicable in three or more fields
Abstract This paper summarizes the histories of geomagnetism and paleomagnetism (1269–1950). The role of Peregrinus is emphasized. In the sixteenth century a debate on local versus global departures of the field from that of an axial dipole pitted Gilbert against Le Nautonier. Regular measurements were undertaken in the seventeenth century. At the turn of the nineteenth century, de Lamanon, de Rossel, and von Humboldt discovered the decrease of intensity as one approaches the equator. Around 1850, three figures of rock magnetism were Fournet (remanent and induced magnetizations), Delesse (remagnetization in a direction opposite to the original), and Melloni (direction of lava magnetization acquired at time of cooling). Around 1900, Brunhes discovered magnetic reversals. In the 1920s, Chevallier produced the first magnetostratigraphy and hypothesized that poles had undergone enormous displacements. Matuyama showed that the Earth's field had reversed before the Pleistocene. Our review ends in the 1940s, when exponential development of geomagnetism and paleomagnetism starts.
Programme 139
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Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 8755-1209 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5486
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Author Flückiger, J.; Monnin, E.; Stauffer, B.; Schwander, J.; Stocker, T.F.; Chappellaz, J.; Raynaud, D.; Barnola, J.-M.
Title High-resolution Holocene N2O ice core record and its relationship with CH4 and CO2 Type Journal Article
Year 2002 Publication Global biogeochemical cycles Abbreviated Journal
Volume 16 Issue Pages
Keywords 0325 Atmospheric Composition and Structure: Evolution of the atmosphere; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 1610 Global Change: Atmosphere; 3344 Meteorology and Atmospheric Dynamics: Paleoclimatology
Abstract Nitrous oxide (N2O) concentration records exist for the last 1000 years and for time periods of rapid climatic changes like the transition from the last glacial to today's interglacial and for one of the fast climate variations during the last ice age. Little is known, however, about possible N2O variations during the more stable climate of the present interglacial (Holocene) spanning the last 11 thousand years. Here we fill this gap with a high-resolution N2O record measured along the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core. On the same ice we obtained high-resolution methane and carbon dioxide records. This provides the unique opportunity to compare variations of the three most important greenhouse gases (after water vapor) without any uncertainty in their relative timing. The CO2 and CH4 records are in good agreement with previous measurements on other ice cores. The N2O concentration started to decrease in the early Holocene and reached minimum values around 8 ka (<260 ppbv) before a slow increase to its preindustrial concentration of ?265 ppbv.
Programme 960
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Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0886-6236 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5545
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Author Eisen, O.; Frezzotti, M.; Genthon, C.; Isaksson, E.; Magand, O.; van den Broeke, M.R.; Dixon, D.A.; Ekaykin, A.; Holmlund, P.; Kameda, T.; Karlöf, L.; Kaspari, S.; Lipenkov, V.Y.; Oerter, H.; Takahashi, S.; Vaughan, D.G.
Title Ground-based measurements of spatial and temporal variability of snow accumulation in East Antarctica Type Journal Article
Year 2008 Publication Reviews of geophysics Abbreviated Journal
Volume 46 Issue Pages
Keywords surface mass balance; East Antarctica; measurements; ground-truthing; 0762 Cryosphere: Mass balance; 0726 Cryosphere: Ice sheets; 0794 Cryosphere: Instruments and techniques; 9310 Geographic Location: Antarctica; 1621 Global Change: Cryospheric change
Abstract The East Antarctic Ice Sheet is the largest, highest, coldest, driest, and windiest ice sheet on Earth. Understanding of the surface mass balance (SMB) of Antarctica is necessary to determine the present state of the ice sheet, to make predictions of its potential contribution to sea level rise, and to determine its past history for paleoclimatic reconstructions. However, SMB values are poorly known because of logistic constraints in extreme polar environments, and they represent one of the biggest challenges of Antarctic science. Snow accumulation is the most important parameter for the SMB of ice sheets. SMB varies on a number of scales, from small-scale features (sastrugi) to ice-sheet-scale SMB patterns determined mainly by temperature, elevation, distance from the coast, and wind-driven processes. In situ measurements of SMB are performed at single points by stakes, ultrasonic sounders, snow pits, and firn and ice cores and laterally by continuous measurements using ground-penetrating radar. SMB for large regions can only be achieved practically by using remote sensing and/or numerical climate modeling. However, these techniques rely on ground truthing to improve the resolution and accuracy. The separation of spatial and temporal variations of SMB in transient regimes is necessary for accurate interpretation of ice core records. In this review we provide an overview of the various measurement techniques, related difficulties, and limitations of data interpretation; describe spatial characteristics of East Antarctic SMB and issues related to the spatial and temporal representativity of measurements; and provide recommendations on how to perform in situ measurements.
Programme 411;454
Campaign
Address
Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 8755-1209 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5492
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Author Augustin, J.; Blomqvist, D.; Szép, T.; Szabó, Z.; Wagner, R.
Title No evidence of genetic benefits from extra-pair fertilisations in female sand martins ( Riparia riparia ) Type Journal Article
Year 2007 Publication Journal of ornithology Abbreviated Journal J. Ornithol.
Volume 148 Issue 2 Pages 189-198
Keywords
Abstract Abstract  Genetic parentage studies of socially monogamous birds reveal a widespread prevalence of extra-pair paternity. Variation in extra-pair paternity among individuals may depend on how different individuals benefit from extra-pair fertilisations and on the opportunity to pursue extra-pair copulations. A long-term study of sand martins (Riparia riparia) in Hungary allowed us to examine patterns of extra-pair fertilisations in a large colony of over 3,000 breeding pairs with many known age individuals. We used multi-locus DNA fingerprinting to determine whether extra-pair fertilisations occur when females are paired to (1) presumably low quality mates, or (2) genetically similar or dissimilar mates, and whether extra-pair fertilisations result in offspring of higher quality. Extra-paternal young were found in 38% of 47 broods and comprised 19% of 190 offspring. Males that lost paternity did not differ significantly from others in age or body condition. Social mates of broods containing extra-pair offspring did not differ in genetic similarity from pairs without extra-pair offspring. Furthermore, there was no significant difference in body condition between extra-pair young and their maternal half-siblings. We were unable to assign paternity and therefore cannot exclude the possibility that extra-pair males differed from the within-pair males they cuckolded, in age, body condition or genetic similarity with the female. We found a positive relationship between paternity losses and breeding density, suggesting that low breeding density may constrain opportunities for seeking extra-pair copulations.
Programme 429
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8375 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5652
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Author Geoffroy, L.; Aubourg, C.; Callot, J.-P.; Barrat, J.-A.
Title Mechanisms of crustal growth in large igneous provinces: The north Atlantic province as a case study Type Journal Article
Year 2007 Publication Geological Society of America Special Papers Abbreviated Journal
Volume 430 Issue 0 Pages 747-774
Keywords traps; volcanic margin; dike swarm; small-scale convection; AMS
Abstract The mechanisms of magma crust accretion at large igneous provinces (LIPs) are questioned using arguments based on the north Atlantic case. Published and new data on the calculated flow vectors within dike swarms feeding the early traps and subsequent seaward-dipping reflector lavas suggest that most of the mafic magmas forming the north Atlantic LIP transited through a small number of igneous centers. The magma was injected centrifugally in dike swarms at some distance away from individual igneous centers along the trend of the maximum horizontal stress acting in the crust, feeding lava piles via dikes intersecting the ground surface. This mechanism is similar to that observed in present-day Iceland and, more generally, in mafic volcano-tectonic systems. The absence of generalized vertical magma transit in a LIP has major geodynamic consequences. We cannot link the surface extent of LIP magmas to the dimensions of the mantle melting zone as proposed in former plume head models. The distribution of LIP magmas at the surface is primarily controlled by the regional stress field acting within the upper crust, but is also affected by magma viscosity. The igneous centers feeding LIPs most likely represent the crustal expression of small-scale convective cells of the buoyant mantle naturally located beneath the mechanical lithosphere.
Programme 290
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Corporate Author Thesis Bachelor's thesis
Publisher Geological Society of America Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0072-1077 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5504
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Author Garcia, S.; Angelier, J.; Bergerat, F.; Homberg, C.; Dauteuil, O.
Title Influence of rift jump and excess loading on the structural evolution of northern Iceland Type Journal Article
Year 2008 Publication Tectonics Abbreviated Journal
Volume 27 Issue Pages
Keywords rift jump; structural evolution; lava dip; dyke; fault; flexure zone; Iceland; 8010 Structural Geology: Fractures and faults; 8036 Structural Geology: Paleoseismology; 8178 Tectonophysics: Tectonics and magmatism; 8137 Tectonophysics: Hotspots, large igneous provinces, and flood basalt volcanism; 9325 Geographic Location: Atlantic Ocean
Abstract New structural data combined with published structural and geochronological data allow reconstruction of the structural evolution that followed the last rift jump across northern Iceland. Tertiary lava flows erupted along the Skagafjördur paleo-rift have been down-bent under the weight of, and in the direction of, Plio-Pleistocene lava flows emitted from the Northern Volcanic Zone and the central part of Iceland. This down-bending process involved development of local flexure zones and a flexural extension along the resulting monoclines. This structural reorganization explains the existence of the Húnaflói-Skagi synform without need for a paleo-rift axis along it, in agreement with previous radiometric dating. The large amount of Plio-Pleistocene lava flows erupted in Central Iceland may have been enhanced by ice cap loading.
Programme 316
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Address
Corporate Author Thesis
Publisher American Geophysical Union Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0278-7407 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (down) IPEV @ Thierry.Lemaire @ Serial 5497
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