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   

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   

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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Fish Assemblages in Shallow Marine Caves of the Salento Peninsula (Southern Apulia, SE Italy)   总被引：1，自引：0，他引：1  

Simona Bussotti  Francesco Denitto  Paolo Guidetti  Genuario Belmonte 《Marine Ecology》2002,23(S1):11-20

Abstract. Fish assemblages of three shallow marine caves from the Salento Peninsula (Apulia, SE Italy) were investigated in July 2000. Data were collected in situ by using visual census. A total of nineteen fish species were recorded inside the caves. The species richness generally displayed a similar pattern in all three caves, decreasing from the entrance towards the innermost sections, whereas the patterns of total fish abundance differed among caves. Apogon imberbis (mainly represented by juveniles) was the most important species in terms of number of individuals (accounting for more than 85% of the censused fish) and showed a fairly even distribution inside the investigated caves. Without the numerical contribution of A. imberbis , fish abundance decreased from the entrance to the inner sections and this pattern was common to all three caves. Juvenile fishes of economic interest ( e. g., Diplodus vulgaris and Epinephelus marginatus ) were also recorded inside. The present study suggests that: (1) environmental constraints could affect distribution patterns in fish species richness and in the abundance of several fish along the axis of "blind caves" (with a single entrance), as already observed for sessile benthos and plankton assemblages; (2) shallow marine caves of the Salento Peninsula could exert the role of refuge and/or nursery for some littoral fish species during the adult and/or juvenile stages of their life histories.  相似文献   

MeMoVolc report on classification and dynamics of volcanic explosive eruptions     

C. Bonadonna  R. Cioni  A. Costa  T. Druitt  J. Phillips  L. Pioli  D. Andronico  A. Harris  S. Scollo  O. Bachmann  G. Bagheri  S. Biass  F. Brogi  K. Cashman  L. Dominguez  T. Dürig  O. Galland  G. Giordano  M. Gudmundsson  M. Hort  A. Höskuldsson  B. Houghton  J.C. Komorowski  U. Küppers  G. Lacanna  J.L. Le Pennec  G. Macedonio  M. Manga  I. Manzella  M. de’ Michieli Vitturi  A. Neri  M. Pistolesi  M. Polacci  M. Ripepe  E. Rossi  B. Scheu  R. Sulpizio  B. Tripoli  S. Valade  G. Valentine  C. Vidal  N. Wallenstein 《Bulletin of Volcanology》2016,78(11):84

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Earthquake early warning feasibility in the Campania region (southern Italy) and demonstration system for public school buildings     

Antonio Emolo  Matteo Picozzi  Gaetano Festa  Claudio Martino  Simona Colombelli  Alessandro Caruso  Luca Elia  Aldo Zollo  Piero Brondi  Nicola Miranda 《Bulletin of Earthquake Engineering》2016,14(9):2513-2529

We present the results of a feasibility study of an earthquake early warning system (EEWS) for the Campania region (southern Italy) using schools as specific targets. The study considered the seismogenic zones as sources of potential earthquakes for the area, the Italian accelerometric network as the recording network for seismic event occurrence, and the performances of the software platform PRESTo ^Plus for data analysis and processing. We analyze the distribution of lead-times for all possible threatening seismic sources for each municipality in the region under study by extracting the lead-time value corresponding to the 5th, 10th and 25th percentiles of the distributions. We discuss the results for the 5th percentile in order to analyze the worst-case scenario: in the case of a single site, the lead-time is expected to be larger than this value in the 95 % of the cases. Since the population distribution in Campania is uneven and most of the people live nearby the coast, whilst the most destructive earthquakes occur along the Apennine chain, we can conclude that an efficient EEWS can allow most of the schools in the area to undertake some mitigating actions. The testing of the EEWS was carried out in the high school ITIS ‘E. Majorana’, located at Somma Vesuviana, about 80 km from the seismogenic Irpinia region. For this purpose, the Sentinel, an actuator made up of low-cost hardware (i.e., Arduino^®), was developed in close cooperation with students and teachers of the school to receive alert messages from the PRESTo ^Plus platform and warn the school users in case of a seismic event. The EEWS and the Sentinel were successfully tested during some blind drills performed during normal school activities.  相似文献