Reflectances transect from coast to open sea, Baltic Sea

In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using 4 different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http.vattenkvalitet.se). The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL) processor, correcting for adjacency effects, improve the retrieval of spectral reflectance for all processors, Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin) processing algorithm, although overestimations in the range 18-26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (< 2.5 mg/m**3), random errors dominated in the retrievals with the MEGS (MERIS ground segment processor) processor. The lowest bias and random errors were obtained with MEGS for suspended particulate matter, for which overestimations in te range of 8-16% were found. Only the FUB retrieved CDOM (Coloured Dissolved Organic Matter) correlate with in situ values. However, a large systematic underestimation appears in the estimates that nevertheless may be corrected for by using a~local correction factor. The MEGS has the potential to be used as an operational processing algorithm for the Himmerfjärden bay and adjacent areas, but it requires further improvement of the atmospheric correction for the blue bands and better definition at relatively low chlorophyll concentrations in presence of high CDOM attenuation.

Annotated record of the detailed examination of Mn deposits from the R/V Galathea II Danish Deep Sea Expedition, 1950-1952

The Danish Expedition of the "Galathea II" around the world brought important results concerning the marine organisms in the deep sea. The "Galathea II" showed not only different organisms of the Abyssal but for the first time of the deepest trenches of the western Pacific. Anton Bruun coined the term Hadal for the region below the Abyssal under 6000 m. Although the "Galathea II" aimed to investigate new deep sea regions beside the routes of former expeditions and to widen the horizon of knowledge relating marine organisms the technical equipment and the methodological approach had partly been developed earlier. The expedition of the "Galathea II" is part of a long tradition of cruises such as that of the British "Challenger", the German "Valdivia" and the Swedish "Albatross" and especially the Danish cruises of the "Dana I" and "Dana II" which happened some years before.

Historical sea ice of the Baltic Sea (1960/61-78/79)

The Baltic Sea is a seasonally ice-covered, marginal sea in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961 to 1978/1979. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised in 1981 in a joint project of the Finnish Institute of Marine Research (today the Finnish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website http://www.baltic-ocean.org hosts the post-processed data and the conversion code.

Major elements and trace ferrides in deep sea cores obtained during the Swedish Deep-Sea Expedition in 1947-1948

Samples from sediment cores collected during the Swedish Deep-Sea Expedition 1947-1948 have been analyzed in the Geochemical laboratory of the Geological Survey of Sweden. Most samples were placed at our disposal by Professor Hans Pettersson, leader of the expedition mentioned. For complementary studies, samples from the Atlantic and Indian oceans were included in our investigation and the samples placed at our disposal by Professor B. Kullenberg, Göteborg. From the Tyrrhenian Sea we got samples from Professor E. Norin, Uppsala.

Stable carbon and oxygen isotope record of live benthic foraminifera from Swedish fjords

In a previous 16-month seasonal study on living (stained) benthic foraminifera from two fjords on the Swedish west coast, it was reported that foraminifera proliferated in response to phytodetritus input; the strongest response came from the opportunistic species Stainforthia fusiformis. In this study, our objective was to find out if that phytodetritus input resulted in a change in the carbon isotopic composition of the foraminiferal tests. We also wanted to examine if variations in salinity and temperature (due to seasonality or deep-water exchanges) were reflected in the delta18O values. From S. fusiformis that were obtained from the Havstens Fjord (20 m) and the Gullmar Fjord (119 m) during the 16-month study, we developed a time series of delta18O and delta13C. After the spring blooms in the Havstens and the Gullmar Fjord, decreases of about 0.2 per mil to 0.3 per mil in the foraminiferal delta13C values were noted; in the Gullmar Fjord after the autumn blooms, decreases of the same order were also noted. Comparing the Havstens and the Gullmar Fjord, we found a 1 per mil difference in both delta13C and delta18O; we attribute this to hydrographic differences between the two fjords. Using calculated values of delta18O, together with the measured ones, we noticed that S. fusiformis in the Gullmar Fjord seems to calcify close to equilibrium with respect to the oxygen isotopes. During autumn, water temperatures were relatively high in the Havstens Fjord, and foraminiferal abundance in the fjord was also high after a phytodetritus input; but, the measured delta18O values do not reflect these higher temperatures. This apparently contradictory combination of results might be explained by a varying delta18O composition of the water during the year, which counterbalances the temperature effect.

Sediment budget and geomorphic process units of the Swedish Kärkevagge, link to ArcInfo E00 files

Geomorphic process units have been derived in order to allow quantification via GIS techniques at a catchment scale. Mass movement rates based on existing field measurements are employed in the budget calculations. In the Kärkevagge catchment, Northern Sweden, 80% of the area can be identified either as a source area for sediments or as a zone where sediments are deposited. The overall budget for the slopes beneath the rockwalls in the Kärkevagge is approximately 680 t/a whilst about 150 t a-1 are transported into the fluvial system.