| Summary: | Annual hydrographic monitoring of Hornsund fjord in southern Svalbard began in 2015. Regular suspended sediment concentration and sediment flux have been monitored since 2015 and 2016, respectively. The observations span over several months, typically from May to October, each year. Vertical CTD (conductivity-temperature-depth) -profiles obtained regularly from 11 stations across the Hornsund fjord form the core of the hydrographic observations. In addition there are several supplementary CTD stations with intermittent observations. The data has been collected using Valeport miniCTD and SAIV A/S SD208 CTD, of which the latter has been accompanied with oxygen and turbidity sensors. Thermodynamic variables (potential temperature, salinity, density and sound velocity) are derived from the raw data. The data has been filtered and the vertical profiles averaged to 1-dbar bins. The data has passed a careful visual quality control. The main focus of the sedimentological observations has been on Hansbukta, one of the several smaller fjord arms in Hornsund. Intermittent observations from other locations across the fjord are also available. Water sampling and sediment flux measurements are regularly obtained from a single point in the center of Hansbukta. In individual years, the distribution of sediment discharge has also been surveyed with sampling across sections parallel and perpendicular to the glacier front. Suspended sediment concentration is measured by filtration of water samples obtained from various depths in the water column. The sediment flux is generally measured either 5 meters above the bottom or below/above the thermocline. The amount of organic matter, expressed as loss on ignition (LOI %), is obtained after combustion. Further details on the data collection and processing can be found in the manuscript mentioned below. The monitoring is still ongoing and the datasets will be updated annually at the data portal of Institute of Geophysics Polish Academy of Sciences ...
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