Seppo Kaitala

AERONET-OC: a Network for the Validation of Ocean Color Primary Products

Abstract The ocean color component of the Aerosol Robotic Network (AERONET-OC) has been implemented to support long-term satellite ocean color investigations through cross-site consistent and accurate measurements collected by autonomous radiometer systems deployed on offshore fixed platforms. The AERONET-OC data products are the normalized water-leaving radiances determined at various center wavelengths in the visible and near-infrared spectral regions. These data complement atmospheric AERONET aerosol products, such as optical thickness, size distribution, single scattering albedo, and phase function. This work describes in detail this new AERONET component and its specific elements including measurement method, instrument calibration, processing scheme, quality assurance, uncertainties, data archive, and products accessibility. Additionally, the atmospheric and bio-optical features of the sites currently included in AERONET-OC are briefly summarized. After illustrating the application of AERONET-OC dat...

Phytoplankton Spring Bloom Intensity Index for the Baltic Sea Estimated for the years 1992 to 2004

We introduce an index for estimating the annual phytoplankton spring bloom intensity in the Baltic Sea. It is based on chlorophyll a estimates calculated from automatically sampled fluorescence and chlorophyll a measurements on board cargo ships from 1992 to 2004. The intensity is described by an index including information on the chlorophyll a concentration and duration of the spring bloom period. In all of the years studied, the spring bloom was most intense in the Gulf of Finland. In the Gulf of Finland and the Northern Baltic Proper there was a slight tendency for the bloom to start earlier in the spring.

Alg@line—joint operational unattended phytoplankton monitoring in the Baltic Sea

Abstract The Baltic Sea is a unique continental brackish water sea. Today the Baltic Sea is eutro- phied and the blooms of harmful planktonic algae are annual phenomena. The blooms are harmful to the marine ecosystem as well as to the recreational and economic use of marine resources. High-quality research gives reliable information on the state of the ecosystem and its changes. Adequate monitoring information is a prerequisite for sound protection measures and only research is able to reliably show the effects of the protection investments. Because the phytoplankton blooms are extremely patchy and temporally rapidly changing, they often remain unobserved when using traditional sampling methods.

Use of ferrybox measurements for the Baltic Sea environment assessment

The spatially heterogeneous character of aquatic life and rapid changes in pelagic communities make it difficult to assess the status of the marine environment using traditional monitoring methods. In order to distinguish between human induced and natural changes in the ecosystem the environmental parameters and the factors affecting them need to be monitored at a wide range of temporal and spatial scales. The capacity of any single monitoring method or strategy should not be overestimated. Instead, different methods complement each other. In the Baltic Sea high frequency recordings of phytoplankton biomass and related environmental parameters (temperature, salinity, nutrients, chlorophyll a) in the near surface layer (4-5m) have been conducted with unattended water sampling onboard several commercial ferries over the last 14 years. The collected data have been used for delivery of almost on-line information for environmental authorities and public, for developing HELCOM indicator fact-sheets and indexes/maps characterising inter-annual and short-term changes of productivity and phytoplankton biomass in different sea areas, and for forecasts of algae blooms. The combination of high frequency automated sampling onboard merchant ships with satellite imagery, traditional sampling and meteorological information has increased the understanding of ecological processes in the Baltic Sea.

Recent advances in ferrybox monitoring on board Finnmaid ferry

Finnish Institute of Marine Research (FIMR) as a founding member of Alg@line consortium has been a forerunner in the field of monitoring research using commercial ferries. In 1992 FIMR started continuous measurements on board the ferry Finnjet, crossing the Baltic Sea Proper, using unattended recording and sampling system. During the spring of 2007 the ferrybox monitoring system was reinstalled in a new ferry Finnmaid providing real time observed data transmission with satellite connection. Chlorophyll-a (Chla) still remains the principal monitoring parameter. However, the distribution of cyanobacteria cannot be evaluated using Chla in vivo fluorescence, as most of their Chla is located in the poorly-fluorescing photosystem I. Instead, phycocyanin (PC) fluorescence is used in the detection of cyanobacterial blooms in 2005-07. PC fluorescence shows a linear relation to the biomass of the bloom forming filamentous cyanobacteria. During blooms of filamentous cyanobacteria the variability in Chla concentrations is better explained by PC fluorescence than by Chla fluorescence. Additionally, Chla records have been applied in validation of MODIS satellite monitoring for the water quality.