Francisco Criado-Aldeanueva

Transport estimates at the western section of the Strait of Gibraltar: A combined experimental and numerical modeling study

[1] Three-yearlong time series of Acoustic Doppler Current Profiler (ADCP) observations at a single station in Espartel Sill (Strait of Gibraltar) were used to compute an outflow of Q2 = � 0.82 Sv through the main channel. The cross-strait structure of the velocity field or the outflow through a secondary channel north of the submarine ridge of Majuan in Espartel section is not captured by observations so that an improved version of a numerical model (CEPOM) has been used to fill the observational gap. Previously, the model performance has been checked against historical data sets by comparing harmonic constants of the main diurnal and semidiurnal constituents from observed and modeled data at different sites of the strait. Considering the great complexity of tidal dynamics in the area, the comparison is quite satisfactory and validates the model to infer the exchange at longer timescales. Using a ‘‘climatological’’ April in the simulation, extracting a ‘‘single station’’ from the model at the same position as the monitoring station and processing the data similarly, the model gives an outflow through the southern channel 13% higher than observations. The inclusion of the cross-strait structure of velocity reduces the computed outflow through the southern channel, whereas the contribution of the northern channel brings the total outflow close to that computed using a single station (5% smaller). If the same correction is applied to observations, the total outflow would reduce to Q2 = � 0.78 Sv. The paper also assesses the importance of eddy fluxes to the total outflow, their contribution being negligible (� 5%).

Evaluation of regional ocean circulation models for the Mediterranean Sea at the Strait of Gibraltar: volume transport and thermohaline properties of the outflow

Abstract A set of simulations from different configurations of the NEMOMED8, NEMOMED12 and NEMOMED36 ocean regional circulation models for the Mediterranean Sea has been studied in order to assess the accuracy of their representation of the exchange through the Strait of Gibraltar. The model volume transport and thermohaline properties of the Mediterranean outflow have been compared with observational data collected at Espartel sill, the westernmost sill of the strait, by a permanent station moored since October 2004 in the frame of the INGRES projects. Results show that, in terms of volume transport, NEMOMED8 simulations perform a better representation of the exchange, while NEMOMED12/36 underestimate both the mean inflow and outflow. The reason for this underestimation is a too low velocity of the flow, which could be consequence of an enhanced roughness effect due the flow-bathymetry interaction. An important improvement in the representation of the exchange seasonality is achieved by the simulations including sea surface height variability of the Atlantic area of the domain. The results for the themohaline characteristics of the Mediterranean outflow are better for NEMOMED12 and NEMOMED36, as a consequence of their better representation of the local dynamical processes that leads to a more realistic composition of the Mediterranean waters comprising the flow.

The Mediterranean Oscillation Teleconnection Index: Station-Based versus Principal Component Paradigms

Two different paradigms of the Mediterranean Oscillation (MO) teleconnection index have been compared in this work: station-based definitions obtained by the difference of some climate variable between two selected points in the eastern and western basins (i.e., Algiers and Cairo, Gibraltar and Israel, Marseille and Jerusalem, or south France and Levantine basin) and the principal component (PC) approach in which the index is obtained as the time series of the first mode of normalised sea level pressure anomalies across the extended Mediterranean region. Interannual to interdecadal precipitation (), evaporation (), -, and net heat flux have been correlated with the different MO indices to compare their relative importance in the long-term variability of heat and freshwater budgets over the Mediterranean Sea. On an annual basis, the PC paradigm is the most effective tool to assess the effect of the large-scale atmospheric forcing in the Mediterranean Sea because the station-based indices exhibit a very poor correlation with all climatic variables and only influence a reduced fraction of the basin. In winter, the station-based indices highly improve their ability to represent the atmospheric forcing and results are fairly independent of the paradigm used.

Large-Scale Atmospheric Forcing Influencing the Long-Term Variability of Mediterranean Heat and Freshwater Budgets: Climatic Indices

AbstractInterannual to interdecadal precipitation P, evaporation E, freshwater budget (E − P), and air–sea net heat flux Q have been correlated with the North Atlantic Oscillation (NAO), eastern Atlantic (EA), eastern Atlantic–western Russia (EA-WR), and Mediterranean Oscillation (MO) climatic indices to explore the influence of atmospheric forcing in the Mediterranean freshwater and heat budget variability. The effect of the MO pattern has similarities with that of the NAO, but MO influence is more intense. On an annual basis, the MO index gives the highest correlation with all the variables considered, and during its negative phase, it exerts a stronger influence than the NAO and is associated with higher P and, especially, enhanced evaporative losses in the Levantine subbasin. The EA pattern does not significantly affect P in the Mediterranean, but a high correlation is found for E and Q from 1979. The EA-WR mode plays a significant role in annual net heat flux since variations in its sign have the pot...

Climatic Indices Influencing the Long-Term Variability of Mediterranean Heat and Water Fluxes: The North Atlantic and Mediterranean Oscillations

ABSTRACT Interannual to interdecadal precipitation (P), evaporation (E), water deficit (E-P), and total heat flux have been correlated with North Atlantic Oscillation (NAO) and Mediterranean Oscillation (MO) indices to explore the influence of large-scale atmospheric forcing on the variability of the Mediterranean water and heat budgets. Basin-averaged precipitation decrease from the mid-1960s to the late 1980s clearly corresponds to a switch from a low to a high state of both indices. The variability of E-P is not so well correlated with the atmospheric indices because of the different sensitivity of E and P that leads to correlations of opposite sign in the eastern and western sub-basins. The effectiveness of the NAO and MO indices is quite similar for P and E-P but the regional MO index has turned out to be a more successful indicator of interdecadal evaporation and net heat flux because, from the mid-1970s to the early 1990s, correlation with the NAO index decreases considerably. Because the MO centre remains relatively steady, it influences most of the Mediterranean Sea year round, so it is more suitable for monitoring long-term water and especially heat budget variability.

The boundary value problem for piezo-electric half space with thin elastic inclusion

The problem of finding mechanical and electric fields in a piezo-elastic half-space with elastic inclusion is considered. The inclusion is loaded with forces of constant intensity. The tangential contact stresses along the contact surface are determined and the behavior of the contact stresses in the neighborhood of singular points is established. By using methods of the theory of analytic functions, the problem is reduced to a singular integro-differential equation in a finite interval. Using an integral transformation a Riemann problem is obtained, and the solution is presented in its explicit form.

The boundary value contact problem of electroelasticity for piecewise-homogeneous piezo-electric plate with elastic inclusion and cut

In this paper a contact problem of the theory of electroelasticity for piecewise-homogeneous plate of piezo-electric material with infinite cut and elastic finite inclusion of variable bending rigidity is considered. By using methods of the theory of analytic function, the problem is reduced to a system of singular integro-differential equations with fixed singularity. Using an integral transformation, a Riemann problem is obtained, the solution of which is presented in explicit form.

The contact problem for a piecewise-homogeneous orthotropic plate with a finite inclusion of variable cross-section

A piecewise-homogeneous elastic orthotropic plate, reinforced with a finite wedge-shaped inclusion, which meets the interface at a right angle and is loaded with normal forces is considered. The normal contact stresses along the contact line are determined and the behavior of the contact stresses in the neighborhood of singular points is established. By using methods of the theory of analytic functions, the problem is reduced to a singular integro-differential equation in a finite interval. Using an integral transformation a Riemann problem is obtained, the solution of which is presented in explicit form.

Stress concentration in an elastic square plate with a full-strength hole

This paper addresses the problem of plate bending for a square weakened with a full-strength hole including the origin of coordinates. The vertices of the square lie on the coordinate axes and its neighbourhoods are cut by the same smooth full-strength arcs which are symmetric with respect to the coordinate axes. Rigid bars are attached to each component of the broken line of the outer boundary of the plate. The plate bends under the action of concentrated moments applied to the middle points of the bars. The unknown part of the boundary is free from external forces. Using the methods of complex analysis, the unknown part of the boundary is found under the condition that the tangential–normal moment takes a constant value. Numerical analysis is performed and the corresponding graphs are constructed.

On the possibility of quantitative definition of knowledge

In this paper, the possibility of quantitative definition of knowledge, information and uncertainty (ignorance) is investigated in such a way, that initial knowledge and useful information in sum would give the final knowledge. Here, the above-mentioned problem is considered in the case of combined uncertainty: probabilistic and possibilistic.