There is a growing need for acoustic channel simulators. Among the reasons for this is the increased interest in underwater acoustic communications, but also the fact that measuring the characteristics of the underwater channel is very expensive. A channel simulator provides access to realistic channels, and allows us to compare algorithms and modulations under identical conditions. Channel sim...

Detecting changes to the transparency of the water column is critical for understanding the responses of marine organisms, such as corals, to light availability. Long-term patterns in water transparency determine geographical and depth distributions, while acute reductions cause short-term stress, potentially mortality and may increase the organisms’ vulnerability to other environmental stresso...

This paper proposes the first model-based clustering algorithm for multivariate functional data. After introducing multivariate functional principal components analysis (MFPCA), a parametric mixture model, based on the assumption of normality of the principal components, is defined and estimated by an EM-like algorithm. The main advantage of the proposed model is its ability to take into accoun...

This paper presents an analysis of sound speed distribution in the Mediterranean Sea based on climatological temperature and salinity data. In the upper layers, propagation is characterised by upward refraction in winter and an acoustic channel in summer. The seasonal cycle of the Mediterranean and the presence of gyres and fronts create a wide range of spatial and temporal variabilities, with ...

[1] The patterns and drivers of phytoplankton primary productivity in the Santa Barbara Channel (SBC) were examined on 16 cruises conducted 3 times each year from 2001 to 2006. Empirical orthogonal function (EOF) analysis revealed 3 modes of variability that explained 89% of the variance in the productivity data set. The first mode, strongest during spring, describes seasonal productivity chang...

in this paper, the two-dimensional triangular orthogonal functions (2d-tfs) are applied for solving a class of nonlinear two-dimensional volterra integral equations. 2d-tfs method transforms these integral equations into a system of linear algebraic equations. the high accuracy of this method is verified through a numerical example and comparison of the results with the other numerical methods.

Introduction This monograph forms an introduction to the theory of orthogonal rational functions. The simplest way to see what we mean by orthogonal rational functions is to consider them as generalizations of orthogonal polynomials. There is not much confusion about the meaning of an orthogonal polynomial sequence. One says that f n g 1 n=0 is an orthogonal polynomial sequence if n is a polyno...

Equatorial planetary waves are a fundamental component of the tropical climate system. Previous studies have examined their structure in the climatological-mean circulation, their role in the climatological-mean momentum balance of the tropics, and their contribution to the climatological-mean upwelling across the tropical tropopause. In this study, the authors focus on the contribution of the ...

A series of seasonally varying linear Markov models are constructed in a reduced multivariate empirical orthogonal function (MEOF) space of observed sea surface temperature, surface wind stress, and sea level analysis. The Markov models are trained in the 1980–95 period and are verified in the 1964–79 period. It is found that the Markov models that include seasonality fit to the data better in ...

[1] A record of regionally significant volcanic eruptions in the North Pacific over the last century has been developed using a glaciochemical record from Eclipse Icefield, Yukon Territory, Canada. Tephrochronology of the Eclipse ice core provides positive identification of the 1907 Ksudach, Kamchatka, the 1912 Katmai, Alaska, the 1947 Hekla, Iceland, and the 1989 Redoubt, Alaska, eruptions. No...