Coordinator: Dr. Nadia Pinardi
Detailed explanation of costs
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- Bu səhifədəki naviqasiya:
- Description of team Institution Personnel Position Man/month
- Detailed explanation of costs 1997 1998
- B.3.4. Construction of a high resolution climatological data set for the Tyrrhenian Sea Principal Scientist: Dr. Gian Pietro Gasparini (SO-CNR, La Spezia)
- Description of team Institute Personnel Position Time(%) Man/month
- TASK B.3.5
- B.3.6 Prognostic and adjoint simulations of the Mediterranean Sea general circulation Principal scientist: Dr. A.Bergamasco (ISDGM-CNR, Venezia)
- Description of Team Institution Personnel Position Man/months
- B.3.7 Application of a model describing the two-way coupling between atmosphere and ocean to the analysis of the Mediterranean climate.
- Description of Team Institution\ Personnel Position Man/month
- TASK B.4 Water column and sediment structure in the deep Mediterranean basins: climate variability experiment Responsible
- Task B.4.1 Hydrodynamic structure, heat fluxes across the sediment-water interface and stratigraphic records of past climatic events
- Description of the team Institute Personnel Position Man/month
- Budget allocated to each team and detailed explanation of costs 1997
- Principal scientist
- Budget allocated to each team and detailed explanation of costs 1998
Detailed explanation of costs 1997 1998 Consum. Travel Personnel Tot. Consum. Travel Personnel Tot. 20 5 10 35 20 5 10 35 B.3.3. The Water Masses Variability in the Tyrrhenian Sea Principal scientist: Dr.Vincenzo Artale ( ENEA-Casaccia, Roma) Background The principal water masses of the Tyrrhenian sea are the Modified Atlantic Water (MAW) and the Levantine Intermediate Water(LIW). The MAW and the LIW flow into Tyrrhenian sea through them Sardinia-Sicily section along the Sicilian coast. Successively, a part of these waters flow northwards. The remaining recirculates and exits through the same section more towards the west. The information coming from Tyrrhenian budget computations indicate that the resulting water balance requires a remarkable amount of mixing between LIW and both the surface and deep waters (DW). Thus the Tyrrhenian Sea appears to store and modify significant amounts of both the LIW, entering into it from the eastern Mediterranean, and the Western Mediterranean Atlantic and Deep Waters. A more accurate evaluation of the basin inflow/outflow and of the interior processes is necessary for a thorough understanding the seasonal and interannual variability of the Tyrrhenian Sea making this basin one of the more important to understand the modified characteristic of the LIW in the western Mediterranean basin. The surface circulation is the most known and is largely influenced by the wind effect and the mean flow, while the intermediate circulation is only approximately known. One of the most interesting experimental results of the La Spezia group are relative to the straits, which indicate as the LIW moves along very narrow stream, largely influenced by the bottom, which are very difficult to follow along the basin. In order to start a more intense interaction between numerical modeling and hydrographic survey we propose to study the Tyrrhenian circulation using the three-dimensional primitive equation model using a new data set. This new data set will be made by the merging of the new measurements performed in the last years by CNR laboratory of La Spezia with climatological data. Therefore the numerical models we plan to use is at high horizontal and vertical resolution (1/12 degree and 50 levels) because we need to resolve very well either of them to study the spreading of the LIW into the basin; finally we intend to force the model with the ECWMF wind stress. Considering the closeness or our scientific interests to those of other scientists participating to the `Progetto Strategico' we are planning to develop all the different phases of the project at tight contact with them. We will integrate into the model the experimental evidence of water mass variability at the strait of Corsica and at the Sardinia Channel (SO-La Spezia) and the results of the recent studies of the wind effect on the Tyrrhenian circulation analyzed by means of a free-surface, barotropic primitive equation (Task B.3.1). Scientific Objectives -to implement an eddy resolving numerical model of the Tyrrhenian Sea using realistic boundary conditions and topography -simulate the water mass transformation into the basin and comparison with the observations Workplan - Analysis of the latest oceanographic surveys for the definition of the open boundary conditions of models - Implementation of the Tyrrhenian high resolution numerical model - Sensitivity experiments to different forcings (wind stress, heat fluxes, etc.) Description of team Institution Personnel Position Man/month ENEA, Casaccia,Roma . Vincenzo Artale Scientist 4 Wolfango Rupolo Scientist 3 Andrea Cappelletti Scientist 3 Paola Picco Scientist 3 Antonio Baldi Technician 3
*All costs are in Millions of Lire Detailed explanation of costs 1997 1998 Consum. Travel Personnel Tot. Consum. Travel Personnel Tot. 20 5 25 20 5 25 B.3.4. Construction of a high resolution climatological data set for the Tyrrhenian Sea Principal Scientist: Dr. Gian Pietro Gasparini (SO-CNR, La Spezia) During the past years various hydrographic studies have yielded quasi-synoptic descriptions of the Tyrrhenian Basin. It is particularly notable at this regard, the IUN Atlas (Aliverti et al., 1968), while some papers (Krivosheya and Ovchinnikov, 1973; Krivosheya, 1983) provided a seasonal description of the geostrophic current fields. Because of some new available surveys, the previous studies and data sets need to be updated. In spite of the existence of the MODB data set (Brasseur, 1995) and the Levitus Atlas 1994 data set, the specific processes present in the area (Hopkins, 1988) need a climatology with very fine resolution. A new data set taking in account the most recent results on the Tyrrhenian circulation (Pistek et al., 1995; Zodiatis and Gasparini, 1996) seems to be important. Our motivation in producing a climatological data set specific for the Tyrrhenian Basin is based on the recognition that this basin is deeply involved in the Mediterranean circulation and plays a crucial role in modifying its hydrographic characteristics. Furthermore, the determination of the water mass properties and circulation of the Tyrrhenian basin seems to be important in the evaluation of the climatic variability of the Mediterranean. The new data set will be used by the modeling subtasks described above. Scientific Objectives - produce a highly resolved climatological data set for the Tyrrhenian, gridded at least at 1/8 degrees of resolution. - merge the data set with the existing MODB data base Workplan -collect and harmonize the data -analyze the data and make a gridded climatology Description of team Institute Personnel Position Time(%) Man/month SO, CNR, La Spezia Gian Pietro Gasparini Scientist 20 3 Carlos Balestrini Scientist 30 4
TASK B.3.5 Studies of the general circulation variability via surface drifters simulations Principal Scientist: Dr. F.Tampieri (IMGA-CNR, Bologna) Background The atmospherically forced interannual variability has been described in recent years by General Circulation Model (GCM) results (Pinardi et al., 1997, Korres et al., 1996). It is now recognized that atmospheric forcing variability at seasonal and interannual time scales can induce changes in the upper ocean structure of the currents. The major driving mechanism resides in the changes of the wind stress curl during the winter which can offset the regular occurrence of summer and winter seasons in the year following a strong winter anomaly in wind stress. The observational evidence for such changes is still scarce: only the Straits measurements described in Task B.1 and the few cruises done by POEM between 1985 and 1988 give an idea of the occurrence of dramatic changes in the upper ocean circulation of the basin. The in situ data requirements for monitoring the changes at the basin level are very large and still far to come. However, in recent years, the Saclant Center in La Spezia has started a surface drifters program which considered tracking of drifters for few years continuously. This is a crucial data set to validate and check hypothesis on the mechanisms which control interannual variability in the Mediterranean Sea due to the large scale coverage which such data can offer. We propose then to implement a drifter simulation within the GCM set up during the past five years at IMGA. This GCM has been elaborated as a result of two Mast Projects funded from 1990 until 1996. It is implemented in the whole Mediterranean area, with daily atmospheric forcing at the air-sea interface and with sophisticated parametrizations of vertical mixing in the water column. For reference see Roussenov et al. (1995). We propose here to use such model and validate the response with comparison to the surface drifters data of Saclant. Scientific Objectives The subtask proposes to study the interannual variability of the Mediterranean Sea induced by atmospheric forcing through simulations with a GCM. The second aim is to diagnose particle trajectories and finally drifters to be able to compare with real data surface drifters such as the Saclant drifters data set for 1994-1995. Workplan -Produce a GCM simulation for the time period 1991-1995. In order to do so acquire 1995 ECMWF data. -Implement lagrangian trajectory simulations for the same time period using different deployment positions. Add Lagrangian turbulence model as described for other world ocean situations (Griffa et al., 1996) -Implement surface drifters simulations to reproduce the Saclant data set, based on stochastic processes (Thomson, 1987, Cesari and Tampieri, 1996). Description of Team Institution Personnel Position Man/month IMGA-CNR (1) Tampieri Scientist 1 Cesari Ph.D. Student 12 SO, La Spezia (2) A.Griffa Scientist 1
*All costs are in Millions of Lire Detailed explanation of costs 1997 1998 Consum. Travel Personnel Tot. Consum. Travel Personnel Tot. Unit 1 20 5 9* 34 20 5 9* 34 Unit 2 20 5 25 20 5 25 59 59 * Partial funding of a Ph.D. student B.3.6 Prognostic and adjoint simulations of the Mediterranean Sea general circulation Principal scientist: Dr. A.Bergamasco (ISDGM-CNR, Venezia) Background The meteorological forcing (wind and buoyancy) are the main causes of the oceanic circulation and its variability. Also the Mediterranean circulation is driven almost in equal proportion by wind stresses and heat fluxes. In order to understand the Mediterranean Sea general circulation and its interannual variability as a response to meteorological forcing variability, a set of prognostic and adjoin calculations will be carried out. Scientific Objectives The main focus will be the description and understanding of the evolution of the thermohaline cell responsible of the seasonal and interannual changes of the circulation. All the experiments will use in situ data both for assimilation and verification of the model results. In particular, the mechanisms of the preconditioning of the intermediate and deep water formation processes in the Eastern Mediterranean will be explored. Workplan To reach the scientific goals we will follow a twofold strategy: 1. Use of prognostic models with high resolution in order to explore the mechanisms determining the water mass formation preconditioning phase, especially localized on the Rhode gyre winter intensification area. The GFDL (Geophysical Fluid Dynamics Laboratory, Princeton, US) and the Princeton Ocean Model (POM), already implemented in the Eastern Mediterranean area will be used. Experimental data from POEM will be used as initial fields and for model validation. Meteorological data from ECMWF will be used to force the Eastern Mediterranean general circulation model. 2. Use the adjoint method applied to the GFDL model, to assimilate available experimental data (temperature and salinity data coming from POEM cruises) to find out the circulation of the Eastern Mediterranean for the last decade and connect with ad hoc experiments to understand the preconditioning mechanisms for Levantine Intermediate Water (LIW). Description of Team Institution Personnel Position Man/months ISDGM-CNR Venezia A.Bergamasco Scientist 2 S.Carniel Scientist 3 E.Pitton Scientist 3 G.Arcari Scientist 3 METU-Erdemli, Turkey T.Oguz Scientist 1
*All costs are in Millions of Lire B.3.7 Application of a model describing the two-way coupling between atmosphere and ocean to the analysis of the Mediterranean climate. Responsible: P.Lionello (Dept. of Physics, Univ. of Padova) Background The whole model structure consists of three modules: The BOLAM (Bologna Limited Area Model) describing the atmospheric circulation, the POM (Princeton Ocean Model) describing the marine circulation, and the WAM (WAve Model) describing the air-sea interface and the dependence of the surface roughness on the wave spectrum. The model accounts for the interaction between atmosphere and ocean by including the feedbacks among the systems. The first version of the model which consists only of the BOLAM and WAM modules has been already applied to the study of the mid-latitudes cyclones and of the Mediterranean cyclogenesis. The addition of the POM module is in progress. The wave model WAM is included because there are both theoretical and experimental evidences of an effect the ocean wave field on the momentum flux. In fact there are indications that the sea surface roughness is a decreasing function of a dimensionless parameter called wave age, implying that, for a fixed wind speed, a young windsea determines a larger momentum flux than an old one. No evidence is presently available for a similar effect on the heat and moisture fluxes remains presently controversial point because no evidence is available for supporting it. This research aims to evaluate the effect of the wave field on the intraseasonal variations of the fluxes in the Mediterranean sea where the presence of complicated coastlines determines the prevalence of young windsea conditions during the storms. Moreover, the use of a coupled atmosphere-sea model, allows the computation of the heat and moisture fluxes using the actual values of the air temperature and humidity, and of the sea surface temperature, avoiding inconsistencies among the forcing of atmospheric and ocean model. Note that this model framework allows easily to account for high spatial and time resolution forcing of the ocean. The proposal implies the use of the model for set of simulations, each with a duration of a few days, studying the behavior of the coupled systems during the passage of the atmospheric cyclones. The basic idea is to analyze selected cases and to obtain an evaluation of the effect of the coupling and of the high time and space resolution of the model on intraseasonal variability of atmosphere and sea in the Mediterranean region, by taking into account the frequency of the cyclones. Scientific Objectives A study of: - the feedback between the atmosphere and the ocean on the intensity of the atmospheric cyclones in the Mediterranean Sea. - the role of the feedback between atmosphere and ocean on the Mediterranean Climate - the intermittence of the deep water formation and of the process during favorable meteorological conditions - the role of the ocean wave field in the exchange of momentum, heat and moisture in the Mediterranean Sea, eventually correcting the estimate of the intraseasonal variations of the air-sea fluxes. Workplan - Complete the inclusion of the module POM in the complete model - Simulate a series of selected cyclogenesis and passages of atmospheric cyclones - Analyze the change of the sea stratification produced by the passage of the cyclone - compare the high space and time resolution air-sea fluxes computed by the model with the climatic values and assess the potential benefits of the coupled simulations. Description of Team Institution\ Personnel Position Man/month Univ of Padova P.Lionello Researcher 3 FISBAT P.Malguzzi Scientist 1 FISBAT A. Buzzi Scientist 1 ISDGM A.Bergamasco Scientist 1
*All costs are in Millions of Lire TASK B.4 Water column and sediment structure in the deep Mediterranean basins: climate variability experiment Responsible: Dr. Bruno Della Vedova (DINMA, Trieste) In the past decade the Eastern Mediterranean has been the site of a climatic change in the deep ocean structure which could affect for many decades the thermohaline circulation of the Eastern Mediterranean. The deep water masses of the Eastern Mediterranean have been traditionally found to be formed of Adriatic deep waters, exiting the Otranto Strait and diffusing slowly in the whole central Mediterranean basin. In the late eighties-early nineties, however, a warmer and denser water mass than the deep Adriatic waters outflew from the Aegean Sea and renewed the deep central Mediterranean layers. This climatic event has been traced in the oceanographic records acquired within the international cooperative POEM (Physical Oceanography of the Eastern Mediterranean) research Program ( Roether et al., 1996; Malanotte-Rizzoli et al., 1996). The thermal transient associated to this warming event has been memorized in the sediment thermal history and was measured by the MEDRIFF (An Integrated Investigation of the Fluid-Flow Regime of the Mediterranean Ridge) Consortium (Della Vedova et al., 1996). The analysis of the MEDRIFF thermal data allowed to reconstruct the space and time variability of the warming event across a 300 km long transect from the Aegean strait, west of Crete, to the Ionian abyssal plain (Della Vedova et al., 1996). Measurements collected in the same area at different times indicated that the thermal structure in the bottom-water and sediments had been modified significantly on weekly, monthly, and interannual time-scales. Modeling of the conductive heat propagation into the sediment explains the observed thermal anomalies assuming up to 0.6°C warming of the bottom-waters that propagated southwestwards from the Hellenic Trench to the crest area of the Mediterranean Ridge. The sediment warming started in summer 1992 in the Matapan Trench and reached the Mediterranean Ridge crest in late 1992-early 1993, with an attenuated thermal pulse of +0.1°C in amplitude. The average spreading velocity of the sediment warming is about 0.7-0.9 km/day. A challenging question arises whether this change in the thermohaline circulation is resulting from a time constrained convergence of climatic factors or it is an early stage of a cyclic, longer time scale event, like those which left sapropels in the sediments as records of their occurence (Cita et al., 1991). We assume that , since its appearence, it is affecting biogeochemical cycling in this area and its effects can be assessed in the the trophic balance and in the benthic pelagic coupling. The target of Task B4 is therefore to follow the evolution of this regional change and define its effects on biogeochemical parameters in the water column, at the water-sediment interface and in the deep sediments. This research is essentially based on measurements of fluxes of materials and energy between the three compartments (water column, surface sediment and deep sediment): downward fluxes of particles from the photic layer to the sea floor, fluxes of heat and dissolved species across the water-sediment interface, and into the deep sediment. The experimental work will be carried out in a corridor along the thermohaline pathway of this newly formed deep water mass, where oceanographic conditions and sea floor morphology allow the signals to be recorded in the sediments. A feasibility study for the deployment of a deep sea observatory is one of the expected outputs of this task. The station will be designed to provide a long-term climatic monitoring of the marine ecosystems, by continuous measurements of physical parameters. The site will be also selected on the basis of previous (POEM-BC Program) and ongoing oceanographic investigations (EU-MATER, SINAPSI: this Task and Task B5.1) Task B4.1 concerns oceanographic measurements in the water column, heat flux measurements in the sediment and core sampling. The cores will be also analysed for biostratigraphic and geochemical palaeoenvironmental proxies. The Task B.4.2 concerns the assessment of biogeochemical fluxes based on data from the above mentioned field experimental station Task B.4.1 Hydrodynamic structure, heat fluxes across the sediment-water interface and stratigraphic records of past climatic events (in close connection with Subproject D) Principal scientist: Prof. Bruno Della Vedova (DINMA - TS) Background The sediment is a large archive of information of the events which affected the past history of the basin. The sedimentary sequence keeps record of the geological evolution of the basin and the surrounding margins, of the changing physical characteristics of the water masses and of the evolution of the marine ecosystems. In particular a detailed study on the anoxic sediments will be continued; they keep record of the fluxes of biogenic material from the water column to the sediments and thus also of the changes consequent to climatic events of this kind. The integration of geological, geophysical, chemical and biological studies would allow us to recognize evidences for climate changes and cyclic events. The thermal transients on the seafloor are temporary memorized in the sediment, this process provides us an important information on the time evolution of the sea bottom warming process. . Scientific Objectives The general objective of our investigation will be to study and to recognize changes in the water column, sediment structure (physics, chemistry and biology) of the deep Mediterranean Basin, related to climate variability at different time scales. To achieve this, the following specific objectives of this subtask are proposed:
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