Variations in a set of optical and hydrologic parameters of the Atlantic surface waters

A complex analysis of the hydrooptical and dynamic parameters of the Atlantic surface waters has been made on the basis of experimental data. It is shown that the structural properties of the distribution of the basic hydrooptical parameters—such as the optical water-type index m (according to Prof. V.N. Pelevin’s classification), surface-water transparency (the depth of white-disc visibility Z _σ), circulation parameter (the dynamic height D at a depth of 100 m), and flow fields—are similar. On the basis of this, in the authors’ previous studies, relations between these parameters were obtained and the empirical dependences Z _σ(m) and D(m) were found. These dependences and the earlier obtained relationships between biological and optical parameters-chlorophyll concentrations c _p (m) and the indices of light attenuation by a soluted “yellow substance” a _ys (m) and suspended matter a _sm (m)—were combined and formed the basis of a method to determine them at any point of the open ocean from the measured (also remotely) parameter m. The results of the measurements of hydro-optical parameters (which were taken as part of the Meridian project from the Akademik Ioffe during its 14th voyage in October-November 2003) supported the validity of calculations of variations in the five parameters indicated above from the values of the index m. Thus, the efficiency of the developed rapid method of estimating variations in a set of parameters according to the optical water-type index m was demonstrated. In addition, the water’s “health” index H _w proposed by Pelevin in 2002, which is equal to the ratio between chlorophyll concentrations and soluted yellow substance, proved to be efficient at identifying the ecological state of the near-surface waters.