Variability of bio-optical parameters in Lake Jasień Północny and Lake Jasień Południowy
Bio-optical properties of water in two lakes from the Bytow district, Jasień Południowy (JS) and Jasień Północny (JN), were measured between 2007 and 2010. These lakes were chosen as reference for research in the Regional Environment Monitoring System (Wojewódzki Program Monitoringu Środowiska) between 2007 and 2009. The research concerned mainly OSCs (Optically Significant Constituents) such as chlorophyl a, SPM (Suspended Particulate Matter), CDOM (Colored Dissolved Organic Matter) and optical parameters of water (Secchi depth zSD, diffuse light attenuation coefficient Kd, PAR). The aim of this article is to present temporal variability of OSC and optical properties in the investigated lakes as well as the relation between OSCs and the optical properties of water. The research has shown that the variability in the properties of water of these lakes is quite significant: concentration of chlorophyl CChl varied from 1.3 to 32.3 mg m-3 and the Kd, PAR coefficient from 0.42 to 1.05 m-1. The obtained results were compared with the same parameters from other lakes in this region. The variability in the optical properties depend on the season and the biological activity of phytoplankton. Regression analyses showed a high correlation of optical properties of water with CChl and CSPM, and no correlation with CDOM concentration. The highest determination coefficient was obtained for the optical parameters correlated with the three OSCs. The presented results show not only annual variability and variability between the years but also an influence of OSC elements on the optical properties of lakes.
Eutrophication parameters and Carlson-type trophic state indices in selected Pomeranian lakes
The objective of the study (2007-09) was to determine the current trophic state of eight selected lakes - Rybiec, Niezabyszewskie, Czarne, Chotkowskie, Obłęże, Jasień Południowy, Jasień Północny, Jeleń - based on Carlson-type indices (TSIs) and, to examine the relationship between the four calculated trophic state indices: TSI(SD), TSI(Chl), TSI(TP) and TSI(TN). Based on these values, it can be claimed that the trophy level of the lakes are within the mesotrophic and eutrophic states. It was observed that the values of the TSI(TP) in the analysed lakes are higher than the values of the indices calculated on the basis of the other variables. Moreover, the differences between the indices for particular lakes, suggest that in none of the analysed lakes is phosphorus a factor which limits algal productivity.
Recently developed system for assessment of radiation budget for the Baltic Sea has been presented and verified. The system utilizes data from various sources: satellite, model and in situ measurements. It has been developed within the SatBałtyk project (Satellite Monitoring of the Baltic Sea Environment - www.satbaltyk.eu) where the energy radiation budget is one of the key element. The SatBałtyk system generates daily maps of the all components of radiation budget on every day basis. We show the scheme of making daily maps, applied algorithms and empirical data collection within the system. An empirical verification of the system has been carried out based on empirical data collected on the oil rig placed on the Baltic Sea. This verification concerned all the components of the surface radiation budget. The average daily NET products are estimated with statistical error ca. 13 Wm-2. The biggest absolute statistical error is for LWd component and equals 14 Wm-2. The relative error in relation to the average annual values for whole Baltic is the biggest for SWu and reaches 25%. All estimated components have correlation coefficient above 0.91.