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Frida A-M. Bender 《Surveys in Geophysics》2012,33(3-4):693-700
This paper summarizes the discussions held during the session dedicated to Aerosol forcing at the Workshop Observing and Modelling Earth’s Energy Flows. The session Aerosol forcing was convened by P. Ingmann and J. Heintzenberg and included 10 presentations given by R. Kahn, D. Winker, U. Baltensperger, J. Haywood, S. Schwartz, J. Heintzenberg, H. Le Treut, U. Lohmann, R. Wood, and E. Philipona. The presentations given ranged from overviews of current observational capabilities to analyses of aerosol–cloud interactions in observations and models of varying complexity. This paper is organized around a few key points, summarizing the major points of agreement, disagreement, and discussion that the presentations gave rise to. The focus is largely on the uncertainties that remain with regard to aerosol forcing, particularly related to aerosol-cloud interactions and indirect aerosol effects on climate. 相似文献
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Stratigraphy and fluvial sedimentary facies of the Neocomian lower Strzelecki Group,Gippsland Basin,Victoria 总被引：1，自引：0，他引：1
A-M. P. Tosolini S. McLoughlin A. N. Drinnan 《Australian Journal of Earth Sciences》2013,60(6):951-970
The Strzelecki Group incorporates Berriasian to Albian, fluvial sediments deposited in the Gippsland Basin during initial rifting between Australia and Antarctica. Neocomian strata of the lowermost Strzelecki Group are assigned to the Tyers River Subgroup (exposed in the Tyers area) and the Rhyll Arkose (exposed on Phillip Island and the Mornington Peninsula). The Tyers River Subgroup incorporates two formations: Tyers Conglomerate and Rintoul Creek Formation. The latter is subdivided into the Locmany and Exalt Members. Ten fluvial sedimentary facies are identified in the lowermost Strzelecki Group: two gravelly facies; four sandy facies; and four mudrock facies. Associations of these facies indicate: (i) prevalence of gravelly braided‐river and alluvial‐fan settings during deposition of the Tyers Conglomerate; (ii) more sluggish, sandy braided to meandering fluvial systems during Locmany Member sedimentation; and (iii) a return to active, sandy, braided‐river settings for deposition of the Exalt Member. The Tyers Conglomerate and Rhyll Arkose rest on an irregular erosional surface incised into Palaeozoic rocks of the Lachlan Fold Belt. The overlying Rintoul Creek Formation incorporates more mature sediments where lithofacies associations varied according to base‐level change, variations in subsidence rates, and/or tectonic uplift of the principal sedimentsource terranes to the northwest. 相似文献
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Carbon cycle studies based on the distribution of O2 in air 总被引：1，自引：1，他引：0
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Frida A-M. Bender 《Theoretical and Applied Climatology》2011,105(3-4):529-535
In an ensemble of general circulation models, the global mean albedo significantly decreases in response to strong CO2 forcing. In some of the models, the magnitude of this positive feedback is as large as the CO2 forcing itself. The models agree well on the surface contribution to the trend, due to retreating snow and ice cover, but display large differences when it comes to the contribution from shortwave radiative effects of clouds. The ??cloud contribution?? defined as the difference between clear-sky and all-sky albedo anomalies and denoted as ??CC is correlated with equilibrium climate sensitivity in the models (correlation coefficient 0.76), indicating that in high sensitivity models the clouds to a greater extent act to enhance the negative clear-sky albedo trend, whereas in low sensitivity models the clouds rather counteract this trend. As a consequence, the total albedo trend is more negative in more sensitive models (correlation coefficient 0.73). This illustrates in a new way the importance of cloud response to global warming in determining climate sensitivity in models. The cloud contribution to the albedo trend can primarily be ascribed to changes in total cloud fraction, but changes in cloud albedo may also be of importance. 相似文献
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Bodin N Abarnou A Fraisse D Defour S Loizeau V Le Guellec AM Philippon X 《Marine pollution bulletin》2007,54(6):657-668
Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analysed in the muscle of various edible marine crustaceans (spider crab, edible crab, velvet swimming crab and Norway lobster) from the Brittany and Normandy coasts (France). The highest concentrations were measured in species collected from Antifer (Seine Bay). PCB and PBDE patterns in crustacean muscles were similar and independent of the geographical area with the predominance of the high chlorinated PCBs (CB153, 138, 118 and 180), and of a few PBDE congeners (BDE47, BDE99, BDE100 and BDE28). Oppositely, dioxin contamination differed with site. The major component in crustaceans from the Seine Bay was 2378-TCDF, whereas specimens from cleaner areas had higher relative concentrations of OCDD. Finally, the comparison of the spider crab contaminant profiles to those measured in mussel and sea bass highlighted two different trends: decapod crustaceans possess relatively strong capacity to metabolise PCBs and PBDEs; however these species might be used as bioindicators for dioxin pollution monitoring in the marine coastal environment. 相似文献
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Samples collected by the Tamayo scientific team both by dredgingand by submersible along 75 km of the East Pacific Rise (EPR)up to its intersection with the Tamayo fracture zone allow explorationof the systematics of ocean ridge basalt petrogenesis in thevicinity of a major transform fault. To investigate these systematicstwenty-nine samples of hand-picked glasses have been analyzedfor major elements, REE and other trace elements. There are distinct chemical differences between samples collectedfar from the Tamayo transform and close to the transform. Samplesfurthest from the transform, where the EPR is characterizedby a broad swell, are, for the same MgO content, lower in abundancesof all incompatible elements than samples near the transformwhere the ridge morphology is characterized by a rift. We callsuch chemical systematics the transform fault effect (TFE).Possible models for the transform fault effect include: (1)fractional crystallization at low or high pressure; (2) partialmelting; and (3) open system fractionation and mixing. Thesemodels have been evaluated using accurately calculated liquidlines of descent for the major elements, and an inversion techniquefor the trace elements. Although low and possibly high pressure fractionation are important,partial melting accounts best for the variations among the Tamayoparental magmas. Basalts erupted in close proximity (< 16km) to the transform (‘rift’ samples) are derivedfrom melts generated by smaller extents of melting than thoseerupted farther (45–75 km) from the transform (‘swell’samples). Inversion of the Tamayo trace element data shows thatbatch melting can account quantitatively for the trace elementvariations, provided that the extents of melting are very small(1–5 per cent). Continuous melting seems more physicallyrealistic and allows slightly higher extents of melting althoughthe total amount of melt removed from the mantle would be ofthe order of 5 per cent. Both melting models account for thedata better if the swell samples are derived from magmas formedat greater depths where garnet is a stable phase while the riftsamples are derived at shallower levels where garnet is notstable. This suggests that melting may occur near the garnet/spinelphase transition in the mantle. The lesser extents of meltingnear the transform could be caused directly by the cooling effectsof ridge truncation, or by perturbation of mantle flow and magmadynamics at ridge/transform intersections. Examination of theTFE at many other ridge/transform intersections is necessaryto distinguish among these possibilities. 相似文献
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