Independent components of spatial-temporal structure of chlorophyll a patterns in the upper layer of the north-western shelf of the Black Sea

Natalya Kyrylenko,Vladyslav Evstigneev

doi:10.3897/oneeco.6.e73269

Abstract

In the present study, the results of independent component decomposition of satellite-derived chlorophyll a (Chla) patterns for the north-western part of the Black Sea are presented. The study has been carried out on the basis of the DINEOF-reconstructed dataset of 8-day average log-transformed Chla (alChla) patterns for 1997-2016. The alChla patterns were decomposed into six independent components of its spatio-temporal variability in the north-western shelf of the Black Sea. The independent components reflect the spatial distribution of alChla anomalies which are likely to be formed under the influence of sea circulation factors driven by wind. The paper presents the results of the analysis of the intra-annual variability of independent components. The interpretation of the patterns of intra-annual independent components variability is given, taking into account the seasonal variability of the wind factor, the flow of the Danube, the Dnieper and Southern Bug rivers and the fact of modulation of independent components dynamics by seasonal phytoplankton succession.

Highlights

IntroductionThe main pycnocline, formed as a result of this, limits the ventilation of the lower layers of the Black Sea (below 150 m)
The Black Sea is a semi-enclosed basin with limited water exchange through the Bosphorus Strait with the Mediterranean Sea
The aim of this study is to identify the main types of spatio-temporal structure of Chla patterns, which are formed under the influence of hydrodynamic factors of the marine environment in the surface layer of the north-western shelf zone of the Black Sea

Summary

Introduction

The main pycnocline, formed as a result of this, limits the ventilation of the lower layers of the Black Sea (below 150 m). Only the upper oxygen-containing thin layer (60-200 m) provides the conditions for the existence of biota (Oguz et al 2012, Pokazeev et al 2020). These factors, along with a rather vast shelf zone in the north-western part of the Black Sea with its own characteristics of biogeochemical processes, determine the spatio-temporal heterogeneity of the functioning of the sea ecosystem (BEGUN et al 2010). The recent studies have focused on drivers and seasonal variability of harmful hypoxia events (Capet et al 2013)

Objectives

Results

Conclusion