Observations in the Gulf of Lions (northwestern Mediterranean Sea) summer have shown that gusts wind lasting a few days generate transient upwellings and inertial motions. Oscillations at frequency were observed current meter data near shore 10% greater temperature data. Vertical coherences show strong baroclinic mode frequencies than frequency. A simple one-dimensional two-layer model suggests these motions are associated with two different physical processes. The first process describes...

Deep-water formation (DWF) in the northwestern Mediterranean Sea and subsequent horizontal circulation are investigated a rectangular basin with three-dimensional primitive equation model. The is forced by constant climatological heat salt fluxes. Convective motion parameterized simple nonpenetrative convective adjustment process plus Richardson number–dependent vertical eddy viscosity diffusivity. A homogeneous column of dense water progressively formed forcing area. Meanders 40-km...

The present paper shows that a wide class of complex transfer functions encountered in geophysics can be efficiently modeled using neural networks. Neural networks approximate numerical and nonnumerical functions. They provide an optimum basis nonlinear allowing uniform approximation any continuous function. also realize classification tasks. It is shown the classifier mode related to Bayes discriminant functions, which give minimum error risk classification. This useful for extracting...

Observations of low‐frequency waves in the Ligurian Sea December 1977 are presented. From time series thermal infrared images obtained by satellite NOAA 5, mean wavelength and phase velocity estimated. They are, respectively, 38 km 18 cm s −1 . These analyzed as large‐amplitude baroclinic waves. Fairly good agreement is found with a two‐layer model.

The impact of the atmospheric forcing on winter ocean convection in Mediterranean Sea was studied with a high‐resolution general circulation model. major areas focus are Levantine basin, Aegean‐Cretan Sea, Adriatic and Gulf Lion. Two companion simulations differing by horizontal resolution were compared. first simulation (MED16‐ERA40) forced air‐sea fields from ERA40, which is ECMWF reanalysis. second (MED16‐ECMWF) ECMWF‐analyzed surface that have twice as high those ERA40. analysis standard...

The statistical properties of the flow structure in Yucatan Channel's main section based on 2 years continuous observations (August 1999 to June 2001) are compared with those simulated by Océan Parallélisé (OPA) primitive equation model two different configurations: ATL6 configuration from CLIPPER project (the whole Atlantic domain a 1/6° resolution), and Prototype Atlantique Méditerranée (PAM) MERCATOR North 1/12° resolution). While observed 2‐year mean transport into Gulf Mexico is 23.06...

The present paper deals with two-dimensional transient upwelling in a two-layer ocean of constant depth. Motions generated by several atmospheric forcings are investigated. Using asymptotic expansions time, it is shown that the component wind parallel to coast generates an interface elevation which propagates along as internal Kelvin wave front. Strong horizontal baroclinic motions linked this phenomenon. velocity within deep layer opposite direction on surface. It found spin-up time mean...

Spectral absorption coefficients of phytoplankton can now be derived, under some assumptions, from hyperspectral ocean color measurements and thus become accessible space. In this study, multilayer perceptrons have been developed to retrieve information on the pigment composition size structure these spectra. The retrieved variables are main groups (chlorophylls a, b, c, photosynthetic nonphotosynthetic carotenoids) relative contributions three algal classes (pico-, nano-,...

Abstract The Sicily Channel surface circulation is investigated by analyzing the outputs of a high‐resolution ocean model MED12 forced during 46 years ARPERA atmospheric fields. Applying neural network classifier, we show that in can be decomposed into 8 modes characterizing major patterns circulation, particularly Algerian Current separation at entrance to Channel, features Atlantic Tunisian and Ionian Stream. These reflect variability space time seasonal inter‐annual scales. Some...

Abstract We present a new method to identify phytoplankton functional types (PFTs) in the Mediterranean Sea from ocean color data (GlobColour study) and AVHRR sea surface temperature. The principle of is constituted by two very fine clustering algorithms, one mapping relationship between satellite pigments other PFTs. algorithms are efficient self‐organizing maps, which neural network classifiers. were able estimate percentage six PFTs: haptophytes, chlorophytes, cryptophytes, Synechococcus...

Abstract This study presents a method for estimating secondary phytoplankton pigments from satellite ocean color observations. We first compiled large training data set composed of 12,000 samples; each sample is 10 in situ high‐performance liquid chromatography (HPLC)‐measured pigment concentrations, GlobColour products chlorophyll‐a concentration, and remote sensing reflectance (Rrs(λ)) at different wavelengths, addition to advanced very high resolution radiometer sea surface temperature...

The large-scale processes preconditioning the winter deep-water formation in northwestern Mediterranean Sea are investigated with a primitive equation numerical model where convection is parameterized by non-penetrative convective adjustment algorithm. ocean forced momentum and buoyancy fluxes that have gross features of mean forcing found MEDOC area. wind-driven barotropic circulation appears to be major ingredient phase formation. After three months, response dominated strong cyclonic...

Abstract This paper presents a neurovariational method for inverting satellite ocean-color signals. The is based on combination of neural networks and classical variational inversion. radiative transfer equations are modeled by whose inputs the oceanic atmospheric parameters, outputs top atmosphere reflectance at several wavelengths. procedure consists in minimizing quadratic cost function that distance between satellite-observed computed neural-network reflectance, control parameters being...

The shallow water equations applied to a two-layer ocean are solved in order study the cited of capes on upwellings. First, analytical solutions linearized version these given for academic right angle corners. Two cases must be envisaged depending whether or not wind, favorable upwelling, is parallel one coast other. Then, nonlinear by using numerical model dealing with the. finite elements method. Capes various shapes studied. Numerical results can interpreted light solutions. major...

Abstract We revisited the partitioning of Mediterranean Sea into bioregions by processing satellite Surface Temperature (SST) and Chlorophyll‐ a concentration (Chla) from ocean color observations combined with Argo mixed‐layer depth for period ranging 2003 up to 2020. This regionalization was performed using an innovative classification based on self‐organizing maps, so‐called 2S‐SOM. clustered waters seven governed specific physical biogeochemical characteristics. studied interannual...