Spatial-temporal variability of the primary production statistics over the Baltic Sea by means of satellite information

Abstract

Based on a statistical analysis of temporal variability of monthly primary production values calculated from satellite measurements of chlorophyll, the linear trends of the primary production in different parts of the Baltic Sea for different scales of variability are defined. Root-mean-square deviations of the production are assessed for the characteristic range of inter-annual and seasonal time scales. Correlation has been estimated between the variable production value and the main hydrometeorological processes that determine its variability in the Baltic Sea. Using the spectral analysis, we have estimated and mapped amplitudes of the inter-annual and seasonal fluctuations of production. The spatial and temporal structure of the seasonal primary production fluctuations in the Baltic Sea is dealt with. The annual fluctuations and the semi-annual fluctuations are shown to reach their peaks in the region over the sea at about the same time. Estimates of the coherence and phase difference between the primary production change and the full flow divergence of currents are obtained in terms of the cross wavelet analysis. The most stable estimates (with coherence 0.8–0.9) are found at the periods of seasonal fluctuations. The phase lag of the primary production change relative to the full flow divergence are then about 3–6 months. Refs 14. Figs 8. Tables 3.