Consistency and fidelity of Indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products     

Tong Lee  Toshiyuki Awaji  Magdalena Balmaseda  Nicolas Ferry  Yosuke Fujii  Ichiro Fukumori  Benjamin Giese  Patrick Heimbach  Armin Köhl  Simona Masina  Elisabeth Remy  Anthony Rosati  Michael Schodlok  Detlef Stammer  Anthony Weaver 《Dynamics of Atmospheres and Oceans》2010

Monthly averaged total volume transport of the Indonesian throughflow (ITF) estimated by 14 global ocean data assimilation (ODA) products that are decade to multi-decade long are compared among themselves and with observations from the INSTANT Program (2004–2006). The main goals of the comparisons are to examine the consistency and evaluate the skill of different ODA products in simulating ITF transport. The ensemble averaged, time-mean value of ODA estimates is 13.6 Sv (1 Sv = 10⁶ m³/s) for the common 1993–2001 period and 13.9 Sv for the 2004–2006 INSTANT Program period. These values are close to the 15-Sv estimate derived from INSTANT observations. All but one ODA time-mean estimate fall within the range of uncertainty of the INSTANT estimate. In terms of temporal variability, the scatter among different ODA estimates averaged over time is 1.7 Sv, which is substantially smaller than the magnitude of the temporal variability simulated by the ODA systems. Therefore, the overall “signal-to-noise” ratio for the ensemble estimates is larger than one. The best consistency among the products occurs on seasonal-to-interannual time scales, with generally stronger (weaker) ITF during boreal summer (winter) and during La Nina (El Nino) events. The scatter among different products for seasonal-to-interannual time scales is approximately 1 Sv. Despite the good consistency, systematic difference is found between most ODA products and the INSTANT observations. All but the highest-resolution (18 km) ODA product show a dominant annual cycle while the INSTANT estimate and the 18-km product exhibit a strong semi-annual signal. The coarse resolution is an important factor that limits the level of agreement between ODA and INSTANT estimates. Decadal signals with periods of 10–15 years are seen. The most conspicuous and consistent decadal change is a relatively sharp increase in ITF transport during 1993–2000 associated with the strengthening tropical Pacific trade wind. Most products do not show a weakening ITF after the mid-1970s’ associated with the weakened Pacific trade wind. The scatter of ODA estimates is smaller after than before 1980, reflecting the impact of the enhanced observations after the 1980s. To assess the representativeness of using the average over a three-year period (e.g., the span of the INSTANT Program) to describe longer-term mean, we investigate the temporal variations of the three-year low-pass ODA estimates. The average variation is about 3.6 Sv, which is largely due to the increase of ITF transport from 1993 to 2000. However, the three-year average during the 2004–2006 INSTANT Program period is within 0.5 Sv of the long-term mean for the past few decades.  相似文献   

The “Tufo Giallo della Via Tiberina” (Sabatini Volcanic District,Central Italy): a complex system of lithification in a pyroclastic current deposit     

P. Cappelletti  P. Petrosino  M. de Gennaro  A. Colella  S. F. Graziano  M. D’Amore  M. Mercurio  G. Cerri  R. de Gennaro  G. Rapisardo  A. Langella 《Mineralogy and Petrology》2015,109(1):85-101

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Use of sedimentary pigments to infer past phosphorus concentration in lakes     

Piero Guilizzoni  Aldo Marchetto  Andrea Lami  Stefano Gerli  Simona Musazzi 《Journal of Paleolimnology》2011,45(4):433-445

We propose a palaeolimnological method for inferring past total phosphorus (TP) concentrations in lake water from spectrophotometrically-measured sedimentary pigments, particularly total carotenoids (TC). Our approach is based on a highly significant statistical correlation (P < 0.0001) between pigment concentrations (total carotenoids) in the surface sediment of 28 Italian lakes (subalpine, large, deep, shallow, volcanic) and TP concentrations measured in these lakes at overturn when the core was collected. A transfer function was developed from this “training” set, and used to estimate past TP concentrations from pigment concentrations in sediment cores. The results generally agreed with TP values as measured by long-term water quality monitoring programs. Contrasting results were obtained by a comparison with diatom-inferred TP. While the diatom model showed a tendency to overestimate TP values higher than 100 μg l⁻¹, the pigment model correctly estimated TP in lakes when TP was <100 μg l⁻¹, but not when lakes were rich in macrophytes. In fact, lakes with extensive populations of aquatic submersed macrophytes and epiphytes are outliers in terms of the TC versus TP relationship. The root mean square error of prediction of the pigment model is lower than those derived from certain diatom—based inference models. The predicted and residual values are not related to the estimated values and their average is not statistically different from zero. Errors were estimated via a ‘leave-one-out’ re-sampling technique. The proposed method permits rapid and relatively inexpensive determination of reference trophic conditions.  相似文献   

Role of pigments on algal communities and photosynthesis   总被引：2，自引：0，他引：2  

A. Lami  P. Guilizzoni  D. Ruggiu  B. Polli  M. Simona  A. Barbieri 《Aquatic Sciences - Research Across Boundaries》1992,54(3-4):321-330

A one-year study of phytoplankton, primary production and related physical and chemical factors was made in a Swiss basin of Lake Lugano (Lago di Lugano). The chlorophylls and 12 carotenoids were analyzed with a TLC technique. The carotenoid monitoring was considered to be particularly interesting, because the role of these pigments in freshwater algae is still very poorly documented by field studies. The dependence of photosynthesis on several factors was statistically evaluated. Evidence was found of light-adaptation phenomena. The variations of photosynthetic activity and efficiency largely depended on the light regime in the few days before the field observations and on the cellular content of chlorophylls and single carotenoids, whose concentrations in their turn were closely linked with light, temperature, average cell size, and with the actual species assemblage.  相似文献   

The Ottaviano eruption of Somma-Vesuvio (8000 y B.P.): a magmatic alternating fall and flow-forming eruption     

G. Rolandi  S. Maraffi  P. Petrosino  L. Lirer 《Journal of Volcanology and Geothermal Research》1993,58(1-4)

The Ottaviano eruption occurred in the late neolithic (8000 y B.P.). 2.40 km³ of phonolitic pyroclastic material (0.61 km³ DRE) were emplaced as pyroclastic flow, surge and fall deposits. The eruption began with a fall phase, with a model column height of 14 km, producing a pumice fall deposit (LA). This phase ended with short-lived weak explosive activity, giving rise to a fine-grained deposit (L1), passing to pumice fall deposits as the result of an increasing column height and mass discharge rate. The subsequent two fall phases (producing LB and LC deposits), had model column heights of 20 and 22 km with eruption rates of 2.5 × 10⁷ and 2.81 × 10⁷ kg/s, respectively. These phases ended with the deposition of ash layers (L2 and L3), related to a decreasing, pulsing explosive activity. The values of dynamic parameters calculated for the eruption classify it as a sub-plinian event. Each fall phase was characterized by variations in the eruptive intensity, and several pyroclastic flows were emplaced (F1 to F3). Alternating pumice and ash fall beds record the waning of the eruption. Finally, owing to the collapse of a eruptive column of low gas content, the last pyroclastic flow (F4) was emplaced.  相似文献   

Technical paper: FluMo—a mobile fluid–chemical monitoring unit for geothermal plants     

Harald Milsch  Ronny Giese  Mathias Poser  Stefan Kranz  Elvira Feldbusch  Simona Regenspurg 《Environmental Earth Sciences》2013,70(8):3459-3463

A versatile fluid–chemical monitoring unit has been developed in the framework of the geothermal research platform Groß Schönebeck, Germany. It enables selective online and in situ measurements of various physico-chemical parameters at different surface locations of a geothermal fluid loop. Sensors are provided for pressure, temperature, volumetric flow rate, density, pH-value, redox potential, oxygen content, and electrical conductivity. In addition, the apparatus features two fluid samplers to manually collect fluid under in situ conditions and ultimately analyze the solution composition. All devices are mounted on a rack allowing easy transfer of the apparatus to other geothermal plants. The maximum operating pressure and temperature of the unit are 15 bar and 150 °C, respectively. The scientific and technical purpose of the system is to monitor a compositional variability of the produced fluid and chemical processes potentially occurring within the plant. These may result from reactions between the fluid and the surrounding materials, e.g., corrosion. Also, mineral precipitation as a consequence of temperature and/or pressure decrease or oxygen contamination may occur. This information is of paramount importance as so induced reactions might lead to failure of plant components or may damage the geothermal reservoir upon fluid reinjection and thus decrease injectivity.  相似文献   

Erratum to: Performance of the L’Aquila (central Italy) gas distribution network in the 2009 (\mathrm{M}_{\mathrm{W}}\;6.3) earthquake     

Simona Esposito  Sonia Giovinazzi  Ludovica Elefante  Iunio Iervolino 《Bulletin of Earthquake Engineering》2013,11(6):2467-2468

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Moisture variability over the Indo-Pacific region and its influence on the Indian summer monsoon rainfall     

Satyaban B. Ratna  Annalisa Cherchi  P. V. Joseph  S. K. Behera  B. Abish  Simona Masina 《Climate Dynamics》2016,46(3-4):949-965

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Changes in precipitation extremes in Brazil (Paraná River Basin)   总被引：2，自引：1，他引：1  

Leandro Zandonadi  Fiorella Acquaotta  Simona Fratianni  João Afonso Zavattini 《Theoretical and Applied Climatology》2016,123(3-4):741-756

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Long-term volcanic hazard forecasts based on Somma-Vesuvio past eruptive activity     

Lucio Lirer  Paola Petrosino  Ines Alberico  Immacolata Postiglione 《Bulletin of Volcanology》2001,63(1):45-60

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