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| Author | Miroshnichenko, L.I.; Klein, K.-L.; Trottet, G.; Lantos, P.; Vashenyuk, E.V.; Balabin, Y.V.; Gvozdevsky, B.B. | ||||
| Title | Relativistic nucleon and electron production in the 2003 October 28 solar event | Type | Journal Article | ||
| Year | 2005 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 110 | Issue | Pages | ||
| Keywords | relativistic solar cosmic rays; GLE modeling; interplanetary propagation; solar radioemissions; flare ejecta; IMF loop structures; 2104 Interplanetary Physics: Cosmic rays; 2111 Interplanetary Physics: Ejecta, driver gases, and magnetic clouds; 2114 Interplanetary Physics: Energetic particles; 7534 Solar Physics, Astrophysics, and Astronomy: Radio emissions; 7519 Solar Physics, Astrophysics, and Astronomy: Flares | ||||
| Abstract | A flare on 2003 October 28 produced a relativistic particle event at Earth, although the active region AR 10486 was located to the east of the central meridian of the Sun. The paper considers features related to the acceleration at the Sun and the propagation to the Earth of energetic particles in this event, which occurred on a disturbed interplanetary background caused by preceding activity on the Sun and a corotating high-speed solar wind stream. From a study of the onset times of the event at different neutron monitors, we conclude that the earliest arriving solar particles were neutrons. The first relativistic protons arrived a few minutes later. Among relativistic solar protons (RSP), two populations could clearly be distinguished: prompt and delayed ones. The prompt solar protons caused an impulse-like increase at a few neutron monitor stations. The delayed solar protons arrived at Earth 0.5 hours later. Both prompt and delayed relativistic protons arrived at Earth from the antisunward direction. On the other hand, subrelativistic electrons that were traced by their radio emission from meter waves (Nançay Radioheliograph and Decametric Array) to kilometer waves (Wind/WAVES) are accompanied by metric radio emission in the western solar hemisphere, far from the flaring active region. We propose a scenario that reconciles the unusual features of energetic particles at the Earth with the observed structure of the interplanetary magnetic field, which suggests the Earth is at the interface between an interplanetary coronal mass ejection (ICME) and a corotating stream during the event. In this scenario the high-energy protons and electrons are accelerated in the flaring active region, injected into the eastern leg of an ICME loop rooted in the active region, and reach the Earth from the antisunward direction after passing through the summit of the loop. We attribute the promptly escaping subrelativistic electrons to acceleration in the western solar hemisphere and propagation along the nominal Parker spiral. | ||||
| Programme | 227 | ||||
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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 | IPEV @ Thierry.Lemaire @ | Serial | 5625 | ||
| Permanent link to this record | |||||
| Author | Dommergue, A.; Ferrari, C.P.; Gauchard, P.-A.; Boutron, C.F.; Poissant, L.; Pilote, M.; Jitaru, P.; Adams, F.C. | ||||
| Title | The fate of mercury species in a sub-arctic snowpack during snowmelt | Type | Journal Article | ||
| Year | 2003 | Publication | Geophysical research letters | Abbreviated Journal | |
| Volume | 30 | Issue | Pages | ||
| Keywords | 0330 Atmospheric Composition and Structure: Geochemical cycles; 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 1863 Hydrology: Snow and ice; 1065 Geochemistry: Trace elements | ||||
| Abstract | An extensive mercury study was conducted in April 2002 prior to and during the annual melting of a snowpack in a sub-arctic site along the Hudson Bay (Canada). Gas-phase measurements show that the snowmelt coincides with an elemental mercury (Hg°) pulse in the snowpack air far above ambient levels. Additional measurements of inorganic mercury (Hg2+) and methylmercury (MeHg+) in snow pits, in surface snow and in a meltwater sample clearly reveal that most of Hg is removed from the snow during the first days of snowmelt. We estimate that gas-phase exchanges contribute poorly to remove Hg from the snowpack; consequently during a snowmelt day more than 90% of Hg present in the snow surface is likely released with the meltwater. In arctic areas, where Hg accumulates at an accelerated rate in the snow surfaces [
Lu et al., 2001] during mercury depletion events (MDE), the discharge of this toxic and bio-accumulating pollutant in water systems could be a threat to ecosystems and local indigenous populations. |
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| Programme | 399 | ||||
| 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 | 0094-8276 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5642 | ||
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| Author | Cerisier, J.-C.; Marchaudon, A.; Bosqued, J.-M.; McWilliams, K.; Frey, H.U.; Bouhram, M.; Laakso, H.; Dunlop, M.; Förster, M.; Fazakerley, A. | ||||
| Title | Ionospheric signatures of plasma injections in the cusp triggered by solar wind pressure pulses | Type | Journal Article | ||
| Year | 2005 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 110 | Issue | Pages | ||
| Keywords | flux transfer events; cusp; reconnection; flow bursts; solar wind pressure; 2463 Ionosphere: Plasma convection; 2712 Magnetospheric Physics: Electric fields; 2716 Magnetospheric Physics: Energetic particles: precipitating; 2736 Magnetospheric Physics: Magnetosphere/ionosphere interactions; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions | ||||
| Abstract | We describe coordinated observations made on 14 July 2001 simultaneously in the midaltitude cusp by Cluster and at the cusp's ionospheric magnetic footprint by Super Dual Auroral Radar Network (SuperDARN) and Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) during a period of three successive solar wind dynamic pressure pulses. In association with each of these pulses, Cluster observes plasma injections while auroral images from the IMAGE spacecraft show enhanced precipitation in the cusp. Following these plasma injections, channels of fast convection flows are observed in the ionosphere by the SuperDARN radars. On the basis of the spatial and temporal relationships between these various signatures, we analyze the response of the dayside magnetosphere and ionosphere to the pressure pulses as follows: (1) the solar wind dynamic pressure pulses are the drivers of plasma injections from the magnetosheath into the cusp; (2) the ionospheric convection bursts start shortly after the auroral intensifications and their duration is much longer (10 min versus 4–6 min for the auroral intensifications); (3) the convection bursts occur on the poleward side of the cusp precipitation; and (4) the Alfvén waves that are responsible of the transmission of the magnetic stress from the reconnection site to the ionosphere are strongly reflected in the upper ionosphere. This, in addition to possible parallel potential drops, may explain the imperfect mapping of the magnetospheric electric field into the ionosphere during the injections. These observations demonstrate that the convection bursts are “fossil” signatures of the compression–injection process, which is also a signature of reconnection at the dayside magnetopause driven by the interplanetary magnetic field alone. | ||||
| Programme | 312;911 | ||||
| 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 | 0148-0227 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5608 | ||
| Permanent link to this record | |||||
| Author | Meijer, Y.J.; Swart, D.P.J.; Allaart, M.; Andersen, S.B.; Bodeker, G.; Boyd, I.; Braathen, G.; Calisesi, Y.; Claude, H.; Dorokhov, V.; von der Gathen, P.; Gil, M.; Godin-Beekmann, S.; Goutail, F.; Hansen, G.; Karpetchko, A.; Keckhut, P.; Kelder, H.M.; Koelemeijer, R.; Kois, B.; Koopman, R.M.; Kopp, G.; Lambert, J.-C.; Leblanc, T.; McDermid, I.S.; Pal, S.; Schets, H.; Stubi, R.; Suortti, T.; Visconti, G.; Yela, M. | ||||
| Title | Pole-to-pole validation of Envisat GOMOS ozone profiles using data from ground-based and balloon sonde measurements | Type | Journal Article | ||
| Year | 2004 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 109 | Issue | Pages | ||
| Keywords | GOMOS; Envisat; ozone profile; validation; stratosphere; remote sensing; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 0394 Atmospheric Composition and Structure: Instruments and techniques; 3360 Meteorology and Atmospheric Dynamics: Remote sensing; 3394 Meteorology and Atmospheric Dynamics: Instruments and techniques | ||||
| Abstract | In March 2002 the European Space Agency (ESA) launched the polar-orbiting environmental satellite Envisat. One of its nine instruments is the Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument, which is a medium-resolution stellar occultation spectrometer measuring vertical profiles of ozone. In the first year after launch a large group of scientists performed additional measurements and validation activities to assess the quality of Envisat observations. In this paper, we present validation results of GOMOS ozone profiles from comparisons to microwave radiometer, balloon ozonesonde, and lidar measurements worldwide. Thirty-one instruments/launch sites at twenty-five stations ranging from the Arctic to the Antarctic joined in this activity. We identified 6747 collocated observations that were performed within an 800-km radius and a maximum 20-hour time difference of a satellite observation, for the period between 1 July 2002 and 1 April 2003. The GOMOS data analyzed here have been generated with a prototype processor that corresponds to version 4.02 of the operational GOMOS processor. The GOMOS data initially contained many obviously unrealistic values, most of which were successfully removed by imposing data quality criteria. Analyzing the effect of these criteria indicated, among other things, that for some specific stars, only less than 10% of their occultations yield an acceptable profile. The total number of useful collocated observations was reduced to 2502 because of GOMOS data unavailability, the imposed data quality criteria, and lack of altitude overlap. These collocated profiles were compared, and the results were analyzed for possible dependencies on several geophysical (e.g., latitude) and GOMOS observational (e.g., star characteristics) parameters. We find that GOMOS data quality is strongly dependent on the illumination of the limb through which the star is observed. Data measured under bright limb conditions, and to a certain extent also in twilight limb, should be used with caution, as their usability is doubtful. In dark limb the GOMOS data agree very well with the correlative data, and between 14- and 64-km altitude their differences only show a small (2.5–7.5%) insignificant negative bias with a standard deviation of 11–16% (19–63 km). This conclusion was demonstrated to be independent of the star temperature and magnitude and the latitudinal region of the GOMOS observation, with the exception of a slightly larger bias in the polar regions at altitudes between 35 and 45 km. | ||||
| Programme | 209 | ||||
| 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 | 0148-0227 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5620 | ||
| Permanent link to this record | |||||
| Author | Bouhram, M.; Dubouloz, N.; Malingre, M.; Jasperse, J.R.; Pottelette, R.; Senior, C.; Delcourt, D.; Carlson, C.W.; Roth, I.; Berthomier, M.; Sauvaud, J.-A. | ||||
| Title | Ion outflow and associated perpendicular heating in the cusp observed by Interball Auroral Probe and Fast Auroral Snapshot | Type | Journal Article | ||
| Year | 2002 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 107 | Issue | Pages | ||
| Keywords | 2704 Magnetospheric Physics: Auroral phenomena; 2724 Magnetospheric Physics: Magnetopause, cusp, and boundary layers; 7859 Space Plasma Physics: Transport processes; 7867 Space Plasma Physics: Wave/particle interactions | ||||
| Abstract | The spatial properties of ionospheric ion outflows associated with perpendicular heating processes in the cusp are studied using a conjunction study from two satellites and ground radar systems. Low-energy outflowing ions are measured in a wide longitudinal range, between 13,000 and 19,000 km in altitude, over the dayside polar cap by the Hyperboloid experiment aboard the Interball Auroral Probe (AP). These observations are related to conjugate convection field measurements by the Saskatoon-Kapuskasing pair of the Super Dual Auroral Radar Network (SuperDARN). Data analysis suggests that outflowing ions originate from a wide magnetic local time range associated with both the dayside cusp region and the dayside cleft region. A direct cusp crossing by the Fast Auroral Snapshot (FAST) satellite at 2000-km altitude shows a correlation between transverse ion heating in a thin latitudinal region (?1.3°) and the presence of broadband extremely low frequency (BBELF) turbulence, in addition to more intense electrostatic waves near and just above the lower hybrid (LH) frequency. This event is unusual because on the basis of the statistical survey of Freja and FAST data, most of the ion-heating events in the midaltitude auroral zone are correlated with enhanced emissions in the BBELF range. Furthermore, the electron population has energies that are too small to drive LH waves unstable. This event offers the opportunity to analyze the contribution of cusp magnetospheric ion injections to the heating of the ambient H+ and O+ ions. Kinetic instability calculations demonstrate that LH waves are destabilized by the ring distributions, which result from injections of high-energy magnetosheath ions. Calculations show that a preheating mechanism by BBELF turbulence near the ion gyrofrequencies is also required so that LH heating is able to occur. The altitude dependence of the LH perpendicular heating is then analyzed by modeling the transport of the injected magnetospheric ions along magnetic field lines. It is shown that LH heating acts as an additional process from ?2000 up to 10,000 km in altitude. In addition, trajectory calculations show that the low-energy outflowing H+ and O+ ions observed along Interball AP orbit in the polar cap are heated inside the cusp at altitudes extending up to 15,000 km. These results are then assembled to construct a possible heating scenario inside the cusp for this data set. The contribution of the different energization mechanisms to the ion heating as a function of altitude is then discussed. | ||||
| Programme | 312 | ||||
| Campaign | |||||
| Address | |||||
| Corporate Author | Thesis | Bachelor's 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 | IPEV @ Thierry.Lemaire @ | Serial | 5609 | ||
| Permanent link to this record | |||||
| Author | Tomasi, C.; Petkov, B.; Benedetti, E.; Vitale, V.; Pellegrini, A.; Dargaud, G.; De Silvestri, L.; Grigioni, P.; Fossat, E.; Roth, W.L.; Valenziano, L. | ||||
| Title | Characterization of the atmospheric temperature and moisture conditions above Dome C (Antarctica) during austral summer and fall months | Type | Journal Article | ||
| Year | 2006 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 111 | Issue | Pages | ||
| Keywords | radiosounding measurements; precipitable water; Antarctic atmosphere; 3349 Atmospheric Processes: Polar meteorology; 1655 Global Change: Water cycles; 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry; 7539 Solar Physics, Astrophysics, and Astronomy: Stellar astronomy | ||||
| Abstract | Two sets of radiosounding measurements were taken at Dome C (Antarctica) in December 2003 and January 2003 and 2004, using RS80-A, RS80-H, and RS90 Vaisala radiosondes, and from March to May 2005, employing the RS92 model. They were examined following accurate correction procedures to remove the main relative humidity dry bias and the temperature and humidity lag errors. The results showed that a strong cooling usually characterizes the thermal conditions of the whole troposphere from December/January to April/May, with an average temperature decrease from 245 to 220 K at the ground, of around 10 K at upper tropospheric levels, and of more than 15 K in the lower stratosphere. The relative humidity data were found to be affected by dry bias of 5–10%, on average, for the RS80-A and RS80-H Humicap sensors and by smaller percentages for the other sensors. The mean monthly vertical profiles of absolute humidity were found to decrease sharply throughout the troposphere, especially within the first 3 km, and to diminish considerably passing from December/January to March/April/May, with average values of precipitable water decreasing from 0.75 to 0.28 mm, median values from 0.69 to 0.25 mm, and first and third quartiles from 0.60 to 0.22 mm and from 0.87 to 0.34 mm, respectively. The results demonstrate that Dome C (where a permanent scientific station has been open for winter operations since austral winter 2005) is a site of comparable quality to the South Pole for both validation of satellite radiance measurements and astronomic observations in the infrared, submillimetric, and millimetric wavelength range, performed with large telescopes that cannot be carried on satellites. | ||||
| Programme | 908 | ||||
| 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 | 0148-0227 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5528 | ||
| Permanent link to this record | |||||
| Author | Udisti, R.; Becagli, S.; Castellano, E.; Delmonte, B.; Jouzel, J.; Petit, J.R.; Schwander, J.; Stenni, B.; Wolff, E.W. | ||||
| Title | Stratigraphic correlations between the European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok ice cores showing the relative variations of snow accumulation over the past 45 kyr | Type | Journal Article | ||
| Year | 2004 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 109 | Issue | Pages | ||
| Keywords | 0325 Atmospheric Composition and Structure: Evolution of the atmosphere; 1620 Global Change: Climate dynamics; 1863 Hydrology: Snow and ice; 3344 Meteorology and Atmospheric Dynamics: Paleoclimatology; 9310 Information Related to Geographic Region: Antarctica | ||||
| Abstract | High-resolution chemistry analysis and electrical measurements performed on two ice core records (European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok) spanning the last 45 kyr allow stratigraphic correlations by matching volcanic events. Several common events were identified along the two ice cores on the basis of acidity and sulphate spikes in snow layers. Timescales were matched through comparison with isotope (?D) profiles and using the Antarctic cold reversal (ACR) minimum, a 10Be peak, and a dust spike as temporal checkpoints. Ratios of relative snow accumulation at the two sites during the Holocene, in the glacial-interglacial transition and in the last part of the glacial period, were reconstructed by finding the best fit between Dome C and Vostok depths recording the same events. After accounting for thinning of the layers as they are buried within the glacier, the Dome C-Vostok accumulation ratio, expected to be roughly constant from the conventional accumulation-temperature-isotope approach, is 1.12 for the glacial period but increases to as much as 1.44 for a large part of the Holocene. Glaciological effects, mainly related to the geographic origin of the Vostok ice along the Ridge B-Vostok axis, can account for only a minor fraction of this change. Instead, we argue that accumulation variability between the cores stems from differential changes in atmospheric circulation during these respective climatic periods at the two sites. Regional changes in atmospheric circulation are proposed with a negative anomaly in Dome C, a positive accumulation anomaly in Vostok, or a combination of both during glacial climate. Our approach may help to improve ice core dating by: (1) revealing anomalies in accumulation-rate estimation based on the classical thermodynamic method and (2) supporting the necessity to take into account contributions due to changes in atmospheric circulation processes. | ||||
| Programme | 960 | ||||
| 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 | 0148-0227 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5634 | ||
| Permanent link to this record | |||||
| Author | Marchand, M.; Bekki, S.; Denis, L.; Pommereau, J.-P.; Khattatov, B.V. | ||||
| Title | Test of the night-time polar stratospheric NO2 decay using wintertime SAOZ measurements and chemical data assimilation | Type | Journal Article | ||
| Year | 2003 | Publication | Geophysical research letters | Abbreviated Journal | |
| Volume | 30 | Issue | Pages | ||
| Keywords | 0340 Atmospheric Composition and Structure: Middle atmosphere—composition and chemistry; 3210 Mathematical Geophysics: Modeling; 3337 Meteorology and Atmospheric Dynamics: Numerical modeling and data assimilation | ||||
| Abstract | Chemistry Transport Models (CTMs) tend to underestimate very severely NO2 concentrations in the polar lower stratosphere during the winter suggesting that either the NO
x sink is overestimated or a source of NO x is missing in models. We study the night-time decay of polar NO2 because it is controlled by the reaction between NO2 and O3 which is thought to be the main NO x sink at high latitudes winter. The model-calculated night-time decay of polar NO2 is tested using solar occultation measurement of NO2 and O3 taken within the Northern polar vortex by the “Système d'Analyse parObservation Zénithal” (SAOZ) instrument on board of a long duration balloon in February 2000. A trajectory analysis is performed in order to find air parcels which have been sampled at sunset and at sunrise by the SAOZ instrument and have stayed in the dark between the measurements. Sunset (or sunrise) SAOZ measurements are then assimilated in a trajectory photochemical model in a variational mode and compared to the corresponding sunrise (or sunset) SAOZ measurements which are called validation measurements. The results are used to assess the ability of the model to reproduce the observed night-time evolution of NO2. Overall, there is a good agreement between analyzed NO2 and validation measurements indicating that the night-time chemistry of NO2 appears to be properly described by the model. The results do not hint at all at the existence of a NO x source, and certainly not a source strong enough to counteract the NO2 sink (NO2 + O3 reaction). |
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| Programme | 209 | ||||
| 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 | 0094-8276 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5639 | ||
| Permanent link to this record | |||||
| Author | Verhoeven, O.; Rivoldini, A.; Vacher, P.; Mocquet, A.; Choblet, G.; Menvielle, M.; Dehant, V.; Van Hoolst, T.; Sleewaegen, J.; Barriot, J.-P.; Lognonné, P. | ||||
| Title | Interior structure of terrestrial planets: Modeling Mars' mantle and its electromagnetic, geodetic, and seismic properties | Type | Journal Article | ||
| Year | 2005 | Publication | Journal of geophysical research-atmospheres | Abbreviated Journal | J. Geophys. Res. |
| Volume | 110 | Issue | Pages | ||
| Keywords | internal structure; Mars; network science; 5430 Planetary Sciences: Solid Surface Planets: Interiors; 6225 Planetary Sciences: Solar System Objects: Mars; 3672 Mineralogy and Petrology: Planetary mineralogy and petrology | ||||
| Abstract | We present a new procedure to describe the one-dimensional thermodynamical state and mineralogy of any Earth-like planetary mantle, with Mars as an example. The model parameters are directly related to expected results from a geophysical network mission, in this case electromagnetic, geodetic, and seismological processed observations supplemented with laboratory measurements. We describe the internal structure of the planet in terms of a one-dimensional model depending on a set of eight parameters: for the crust, the thickness and the mean density, for the mantle, the bulk volume fraction of iron, the olivine volume fraction, the pressure gradient, and the temperature profile, and for the core, its mass and radius. Currently, available geophysical and geochemical knowledge constrains the range of the parameter values. In the present paper, we develop the forward problem and present the governing equations from which synthetic data are computed using a set of parameter values. Among all Martian models fitting the currently available knowledge, we select eight candidate models for which we compute synthetic network science data sets. The synergy between the three geophysical experiments of electromagnetic sounding, geodesy, and seismology is emphasized. The stochastic inversion of the synthetic data sets will be presented in a companion paper. | ||||
| Programme | 905;907 | ||||
| Campaign | |||||
| Address | |||||
| Corporate Author | Thesis | Bachelor's 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 | IPEV @ Thierry.Lemaire @ | Serial | 5567 | ||
| Permanent link to this record | |||||
| Author | Callot, J.-P.; Geoffroy, L.; Brun, J.-P. | ||||
| Title | Development of volcanic passive margins: Three-dimensional laboratory models | Type | Journal Article | ||
| Year | 2002 | Publication | Tectonics | Abbreviated Journal | |
| Volume | 21 | Issue | Pages | ||
| Keywords | 8109 Tectonophysics: Continental tectonics—extensional; 8120 Tectonophysics: Dynamics of lithosphere and mantle—general; 8159 Tectonophysics: Rheology—crust and lithosphere; 8194 Tectonophysics: Instruments and techniques | ||||
| Abstract | Continental breakup above an anomalously hot mantle may lead to the development of volcanic margins. Volcanic margins are characterized by (1) thick seaward dipping lava flow sequences, (2) central intrusive complexes associated with dyke swarms parallel to the coast, and (3) high seismic velocity bodies in the lower crust attributable to magma underplating. A conceptual model for volcanic margins development has recently been proposed based on onshore studies of the Greenland margins and the British Tertiary Igneous Province. It is proposed that the long-lived central intrusions are genetically linked to underlying persistent zones of mantle fusion. These localized melting domains (or soft spots), equivalent to small mantle diapirs, may locally soften the extending continental lithosphere. The low-viscosity diapirs would (1) localize tectonic strain and (2) feed the volcanic margin with magma. Thus such soft spots can control the along-strike magmatic and tectonic segmentation of volcanic margins. Recent geophysical investigations appear to show that the along-strike structure of volcanic passive margins is compatible with such a segmentation process. Here we present a set of scaled experiments designed to study how such localized rheological heterogeneities in the sub-Moho mantle may have a mechanical effect on continental breakup. Four-layer models were constructed using sand and silicone putties to represent the brittle and ductile layers of both crust and mantle. The soft spots are simulated by low-viscosity silicone putty emplaced within the brittle material. At the scale of the entire breakup zone, the soft spots display an oceanic-type strength profile defining low-strength zones where continental breakup is initiated. The rift orientation and segmentation are strongly controlled by the distribution of the low-viscosity heterogeneities, rather than by the direction of regional extension. The experiments are compared with the geometry and segmentation of the onshore part of the Greenland volcanic margins. | ||||
| Programme | 290 | ||||
| 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 | 0278-7407 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | yes | |||
| Call Number | IPEV @ Thierry.Lemaire @ | Serial | 5547 | ||
| Permanent link to this record | |||||