|
|
Pinglot J.F., Pourchet M., Lefauconnier B. & Creseveur M. (1997). Equilibrium line and mean annual mass balance of Finsterwalderbreen, Spitsbergen, determined by in situ and laboratory gamma-ray measurements of nuclear test deposits. Annals of glaciology, 24, 54–59.
|
|
|
|
Ricaud, P. Gabard, B. Derrien, S. Attie, J.-L. Rose, T. Czekala, H. (2010). Validation of tropospheric water vapor as measured by the 183-GHz HAMSTRAD Radiometer over the Pyrenees Mountains, France. IEEE Geoscience and Remote Sensing Society, 48(5), 2189–2203.
Abstract: The H2O Antarctica Microwave Stratospheric and Tropospheric Radiometers (HAMSTRAD) 183-GHz radiometer has been developed to measure vertical profiles of tropospheric water vapor above Dome C (Concordia station), Antarctica ( 75?06'S, 123?21'E, 3233 m asml), which is an extremely cold and dry environment, over decades. Prior to its installation at Dome C in January 2009, the instrument was deployed at the Pic du Midi (PdM) station ( 42?56'N, 0?08'E, 2877 m asml) in the Pyrenees Mountains, France, over the period covering February-June 2008. Vertical profiles of absolute humidity and integrated water vapor (IWV) as measured by HAMSTRAD were compared with measurements from radiosondes launched in three different sites: Lannemezan (43?07'N, 0?23'E, 610 m asml), France (~30 km northeast from PdM), Bordeaux-Me?rignac Airport (44?49'N, 0?42'W, 50 m asml), France ( ~ 220 km northwest from PdM), and Zaragoza (41?39'N, 0?53'W, 263 m asml), Spain ( ~170 km southwest from PdM). The validation process also used the vertical profiles of tropospheric H2O as measured by the nadir-viewing infrared atmospheric sounding interferometer (IASI) instrument aboard the MetOp-A space platform. The temporal evolution of the HAMSTRAD H2O measurements above the PdM station is very consistent with IASI, sonde, and in situ measurements, tracking the same atmosphere from a dry period in February to a wet period in June. HAMSTRAD showed unrealistic values in periods of well-established snow tempest. While the sensitivity of the HAMSTRAD measurements tends to be degraded 6 km above the altitude of the instrument, namely, above 8877 m asml, the HAMSTRAD measurements seem reasonable at the uppermost retrieval level (namely, 10 km, 12 877 m asml). In May, the wet periods are systematically showing a good agreement between sonde and HAMSTRAD IWV fields and H2O below 6777 m asml but a dry bias of IASI by more than 4-kg m-2 IWV, where- – as outside of these periods, the three data sets behave consistently. Since the best results (mean, standard deviation, bias, and correlation) are obtained when the HAMSTRAD radiometer operates in the very dry conditions of February, namely, in dryness conditions comparable to Dome C summertime values, we are very confident in the optimal use of the instrument when deployed in Antarctica.
Programme: 910
|
|
|
|
Hennion F., Fiasson J.L. & Gluchoff Fiasson K. (1994). Morphological and phytochemical relationships between ranunculus species from îles Kerguelen. Biochem. Syst. Ecol., 22, 533–542.
|
|
|
|
Masarie K.A. & Tans P.P. (1995). Extension and integration of atmospheric carbon dioxide data into a globally consistent measurement record. J. Geophys. Res., 100, 11593–11610.
|
|
|
|
Thiebot Jean-Baptiste, Cherel Yves, Trathan Philip N, Bost Charles-André, . (2012). Coexistence of oceanic predators on wintering areas explained by population-scale foraging segregation in space or time
. ECOLOGY, 93(1), 122–130.
Abstract: Ecological niche theory predicts segregation mechanisms that mitigate potential competition between closely related organisms. However, little is known outside the breeding season, when central-place foraging animals may move on larger scales. This study tested for segregation mechanisms within the same 2007 inter-breeding period on three neighboring populations of avian predators from the southern Indian Ocean: Eastern Rockhopper Penguins Eudyptes filholi from Crozet and Kerguelen and Northern Rockhopper Penguins E. moseleyi from Amsterdam. Using state-of-the-art geolocation tracking and stable isotope analysis techniques, we quantified and compared the ecological niches in time, space, and diet. The three populations showed large-scale movements over deep oceanic waters near the Subantarctic Front, with generally little individual variation. The two neighboring populations of Eastern Rockhopper Penguins showed strikingly distinct distribution in space, while foraging in similar habitats and at the same trophic level (crustacean-eaters). In contrast, Northern Rockhoppers showed marked spatial overlap with birds of the sibling Eastern species, but their temporal delay of two months enabled them to effectively avoid significant overlap. Our results highlight parsimonious mechanisms of resource partitioning operating at the population level that may explain how animals from neighboring localities can coexist during the nonbreeding period.
Keywords: Animals, Carbon Isotopes, Demography, Nitrogen Isotopes, Oceans and Seas, Predatory Behavior, Seasons, Species Specificity, Spheniscidae, Time Factors,
Programme: 109;394
|
|
|
|
Costantini David, Bonadonna Francesco,. (2010). Patterns of variation of serum oxidative stress markers in two seabird species. Polar Research, 29(1), 30–35.
Abstract: Abstract Variation in oxidative stress markers in natural populations may provide a useful background for understanding variation in life history strategies. In this study, we seek to evaluate patterns of variation in levels of reactive oxygen metabolites (markers of oxidative damage), serum antioxidant capacity, and serum concentration of thiols (antioxidants endogenously synthesized) in nestling and breeding blue petrels (Halobaena caerulea) and in breeding Antarctic prions (Pachyptila desolata). Male and female prions and nestling petrels did not differ in any of the oxidative stress markers. The serum antioxidant capacity positively correlated with the sample time in nestling blue petrels. Breeding petrels with higher body condition index had higher serum antioxidant capacity and circulating thiols. Finally, both seabird species showed lower levels of reactive oxygen metabolites and higher levels of serum antioxidant capacity than previously studied bird species.
Keywords: Antioxidants, fasting, oxidative damage, petrels, prions, reproduction,
Programme: 354
|
|
|
|
Hu X G, Liu L T, Kroner C, Sun H P, . (2009). Observation of the seismic anisotropy effects on free oscillations below 4 mHz
. J. Geophys. Res., 114(B7), B07301–.
Abstract: We present observations of significant fundamental spheroidal-toroidal mode coupling at frequencies below 4 mHz in the early part of vertical component records from seismic stations on near-equatorial source-receiver propagation paths after the 26 December 2004 and 28 March 2005 great Sumatra earthquakes. Since the mixed-type coupling induced by rotational Coriolis force are very weak at these selected equatorial-path stations, we investigate what effects mimic the strong Coriolis effects at frequencies below 4 mHz, suggesting that local azimuthal anisotropy in the upper mantle is the most likely explanation for the strong anomalous coupling we observed. In addition, strong anisotropy coupling observed in the frequency band of 14 mHz is always characterized by anomalous small amplitudes of coupled spheroidal modes on the vertical component of seismograph, suggesting that excitation of quasi-toroidal modes by azimuthal anisotropy associates with geometric nodes of fundamental spheroidal modes.
Keywords: seismic anisotropy, free oscillations of the earth, mixed-type mode coupling, 7255 Surface waves and free oscillations, 7208 Mantle, 7299 General or miscellaneous,
Programme: 133
|
|
|
|
Haan D. & Raynaud D. (1998). Ice core record of CO variations during the last two millennia: atmospheric implications and chemical interactions within the Greenland ice. Tellus series a-dynamic meteorology and oceanography, 50B(3), 253–262.
|
|
|
|
Kaeuffer Renaud, Bonenfant Christophe, Chapuis Jean-Louis, Devillard Sébastien, . (2009). Dynamics of an introduced population of mouflon Ovis aries on the sub-Antarctic archipelago of Kerguelen
. Ecography, 33(June 2009), 435–442.
Abstract: A commonly reported pattern in large herbivores is their propensity to irrupt and crash when colonizing new areas. However, the relative role of density-dependence, climate, and cohort effects on demographic rates in accounting for the irruptive dynamics of large herbivores remains unclear. Using a 37-yr time series of abundance in a mouflon Ovis aries population located on Haute Island, a sub-Antarctic island of Kerguelen, 1) we investigated if irruptive dynamics occurred and 2) we quantified the relative effects of density and climate on mouflon population dynamics. Being released in a new environment, we expected mouflon to show rapid growth and marked over-compensation. In support of this prediction, we found a two-phase dynamics, the first phase being characterised by an irruptive pattern best described by the u-Caughley model. Parameter estimates were rm0.2990.005 (maximum growth rate), K473945 (carrying capacity) and S29039396 (surplus) mouflon. With a u3.1890.69 our model also supported the hypothesis that density dependence is strongest at high density in large herbivores. The second phase was characterised by an unstable dynamics where growth rate was negatively affected by population abundance and winter precipitation. Climate, however, did not trigger population crashes and our model suggested that lagged density-dependence and over-grazing were the probable causes of mouflon irruptive dynamics. We compare our results with those of Soay sheep and discuss the possibility of a reversible alteration of the island carrying capacity after the initial over-grazing period.
Programme: 136
|
|
|
|
Courchamp F. & Sugihara G. (1999). Modeling the biological control of an alien predator to protect island species from extinction. Ecological applications, 9, 112–123.
|
|
