Simulations of a Line W-based observing system for the Atlantic meridional overturning circulation     

Matthias Fischer  Arne Biastoch  Erik Behrens  Johanna Baehr 《Ocean Dynamics》2013,63(8):865-880

In a series of observing system simulations, we test whether the Atlantic meridional overturning circulation (AMOC) can be observed based on the existing Line W deep western boundary array. We simulate a Line W array, which is extended to the surface and to the east to cover the basin to the Bermuda Rise. In the analyzed ocean circulation model ORCA025, such an extended Line W array captures the main characteristics of the western boundary current. Potential trans-basin observing systems for the AMOC are tested by combining the extended Line W array with a mid-ocean transport estimate obtained from thermal wind “measurements” and Ekman transport to the total AMOC (similarly to Hirschi et al., Geophys Res Lett 30(7):1413, 2003). First, we close Line W zonally supplementing the western boundary array with several “moorings” in the basin (Line W-32°N). Second, we supplement the western boundary array with a combination of observations at Bermuda and the eastern part of the RAPID array at 26°N (Line W-B-RAPID). Both, a small number of density profiles across the basin and also only sampling the eastern and western boundary, capture the variability of the AMOC at Line W-32°N and Line W-B-RAPID. In the analyzed model, the AMOC variability at both Line W-32°N and Line W-B-RAPID is dominated by the western boundary current variability. Away from the western boundary, the mid-ocean transport (east of Bermuda) shows no significant relation between the two Line W-based sections and 26°N. Hence, a Line W-based AMOC estimate could yield an estimate of the meridional transport that is independent of the 26°N RAPID estimate. The model-based observing system simulations presented here provide support for the use of Line W as a cornerstone for a trans-basin AMOC observing system.  相似文献   

U-Pb Age and geochemistry of zircons from xenoliths of the V. Grib kimberlitic pipe, Arkhangelsk diamond province     

S. G. Skublov  L. P. Nikitina  Yu. B. Marin  L. K. Levskii  N. S. Guseva 《Doklady Earth Sciences》2012,444(1):595-600

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New U-Pb and Sm-Nd ages and P-T estimates for eclogitization in the Fe-rich gabbro dyke in Gridino area (Belomorian Mobile Belt)     

A. V. Berezin  V. V. Travin  Yu. B. Marin  S. G. Skublov  E. S. Bogomolov 《Doklady Earth Sciences》2012,444(2):760-765

New data from isotope geochronology (U-Pb, Sm-Nd) petrological study provide evidence of the Svecofennian age (～1.9 Ga) for eclogitization in the Fe-gabbro dyke inductile shear zones of Gridinrea. P-T estimates of eclogitization were computed using the THERIAK/DOMINO software. A close timing relationship between dyke magmatism and eclogitization is inferred.  相似文献   

Finding of zonal wolframoxiolite and its genetic implication     

V. I. Alekseev  Yu. B. Marin 《Geology of Ore Deposits》2012,54(8):674-675

Wolframoxiolite with a sectorial distribution of components is described from Li-F granite. The ontogenetic features provide evidence for the primary origin of wolframoixiolite and geochemical evolution of the mineral-forming medium.  相似文献   

A methodology for dealing with regional change in integrated water resources management     

Jochen Schanze  Johanna Trümper  Cornelia Burmeister  Dirk Pavlik  Ivan Kruhlov 《Environmental Earth Sciences》2012,65(5):1405-1414

The paper presents a methodology on how to consistently deal with the future change and management options in integrated water resources management (IWRM). It is based on a conceptual framework with a five step procedure for the formulation and analysis of a so-called ‘parameterised regional futures’. Developing and testing the approach for IWRM is realised for the upper part of the Western Bug River catchment (Ukraine). Special attention is paid to scenarios of change covering climate and land use. The future regional climate is downscaled with the model CCLM. Land cover is projected after retrospective change detection and the derivation of prospective algorithms. Parameters of the interrelations between land use and the water cycle are tackled through using the concept of the model PWF-LU. The methodology is currently being tested to analyse the impacts of mid-term regional change and management options on the water cycle of the catchment.  相似文献   

Eocene Age Shortening Deformation in Northern Tibet: Implications Models of Plateau Growth     

Marin CLARK  Lydia STAISCH  Petr YAKOVLEV  HONG Chang  Nathan NIEMI 《《地质学报》英文版》2013,87(Z1):343-344

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Do Cloud Properties in a Puerto Rican Tropical Montane Cloud Forest Depend on Occurrence of Long-Range Transported African Dust?     

Johanna K. Spiegel  Nina Buchmann  Olga L. Mayol-Bracero  Luis A. Cuadra-Rodriguez  Carlos J. Valle Díaz  Kimberly A. Prather  Stephan Mertes  Werner Eugster 《Pure and Applied Geophysics》2014,171(9):2443-2459

We investigated cloud properties of warm clouds in a tropical montane cloud forest at Pico del Este (1,051 m a.s.l.) in the northeastern part of Puerto Rico to address the question of whether cloud properties in the Caribbean could potentially be affected by African dust transported across the Atlantic Ocean. We analyzed data collected during 12 days in July 2011. Cloud droplet size spectra were measured using the FM-100 fog droplet spectrometer that measured droplet size distributions in the range from 2 to 49 µm, primarily during fog events. The droplet size spectra revealed a bimodal structure, with the first peak (D < 6 µm) being more pronounced in terms of droplet number concentrations, whereas the second peak (10 µm < D < 20 µm) was found to be the one relevant for total liquid water content (LWC) of the cloud. We identified three major clusters of characteristic droplet size spectra by means of hierarchical clustering. All clusters differed significantly from each other in droplet number concentration ( \(N_{\rm tot}\) ), effective diameter (ED), and median volume diameter (MVD). For the cluster comprising the largest droplets and the lowest droplet number concentrations, we found evidence of inhomogeneous mixing in the cloud. Contrastingly, the other two clusters revealed microphysical behavior, which could be expected under homogeneous mixing conditions. For those conditions, an increase in cloud condensation nuclei—e.g., from processed African dust transported to the site—is supposed to lead to an increased droplet concentration. In fact, one of these two clusters showed a clear shift of cloud droplet size spectra towards smaller droplet diameters. Since this cluster occurred during periods with strong evidence for the presence of long-range transported African dust, we hypothesize a link between the observed dust episodes and cloud characteristics in the Caribbean at our site, which is similar to the anthropogenic aerosol indirect effect.  相似文献   

First find of cerianite in zircons from metasomatites of the Terskii greenstone belt,Baltic shield     

S. G. Skublov  B. Yu. Astaf’ev  Yu. B. Marin  I. M. Gembitskaya  O. A. Levchenkov 《Doklady Earth Sciences》2009,428(1):1134-1138

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Age,mineral geochemistry,and conditions of the formation of the Shueretskoe garnet deposit (Belomorian Belt)     

S. G. Skublov  L. K. Levskii  Yu. B. Marin  I. M. Gembitskaya  P. Ya. Azimov  A. N. Larionov 《Doklady Earth Sciences》2009,429(2):1542-1548

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Kirishites—high-carbonaceous hairlike fibers associated with volkhovites     

G. T. Skublov  Yu. B. Marin  S. G. Skublov  E. V. Vasil’ev  I. M. Gembitskaya  E. S. Nechaeva  Yu. N. Tarasenko 《Geology of Ore Deposits》2009,51(8):698-711

Kirishites are highly carbonaceous hairlike fibers 30–100 μm in thickness and 3–30 mm long, which jut out as bunches on the surface of cinder and shungite fragments associated with volkhovites (Holocene tectitelike glasses corresponding to the rocks of kimberlite-lamproite-carbonatite series in composition). Kirishite fibers are zonal. Their inner (axial) zone is composed of high-nitrogen proteinlike compounds, whereas the outer zone is essentially carbonaceous, with a high content of organoelemental complexes (Si, Fe) and numerous micrometer-sized anomalies of major, volatile, trace, and ore elements. Longitudinal zoning is established in aposhungite kirishites: the consecutive change of maximum concentrations—K, Na, Cl, C, Mn → C, S, V, Ni, Cu, Zn → S, N, Ba, Te, Pb, Bi, Nd—is traced from the roots of fibers to their ends. It is suggested that as volkhovites were forming, fragments of cinder and shungite underwent partial melting. The highly carbonaceous compounds released due decompression and explosion were squeezed out from fragments and solidified as fibers during fall of fragments on the Earth’s surface.  相似文献