Discharge and transport processes along the German Baltic Sea Coast

Abstract

The western Baltic Sea infront of the German coast is a highly variable dynamical system, dominated by a complex and small-scale morphometry, the water exchange between the Baltic and North Seas, and driven by local wind. Neither data collection, nor satellite images or model simulations alone were able to explain the observed spatial patterns and transport processes. Therefore, all these methods were combined to explain the dynamical features and to systematise them according to the typical local wind pattern and time series. The aim was to develop an instrument for regional authorities which supports the interpretation of coastal water monitoring data and forms a basis for an improved monitoring strategy. Satellite data of sea surface temperature and ocean colour from the sensors NOAA-AVHRR and SeaWiFS were applied for synoptic investigations in the entire region and Landsat-7-ETM+ for regional studies. Model simulations were performed for the western Baltic using a 3D model MOM-3 and for the Szczecin Lagoon using 2D model FEMFLOW. For the first time, regional particularities in the coastal dynamical features and processes are derived for the main wind directions and for transitions between dominant wind situations west and east as derived from wind statistics. The simulated transport of particles released from different coastal and open sea sources indicate the affected areas during changing forcing conditions. The results support the interpretation of acquired coastal monitoring data as well as the assessment and optimisation of the monitoring programme.

One year of continuous measurements constraining methane emissions from the Baltic Sea to the atmosphere using a ship of opportunity

“…Then, upwelling can be detected by a local sharp temperature drop in the surface water, which can last a couple of days. A well-developed method to observe this phenomenon, recurring in time and location, is satellite imaging of the sea surface temperature (Siegel et al, 1994(Siegel et al, , 2005Lass et al, 2010).…”

Climate change and the Baltic Sea action plan: Model simulations on the future of the western Baltic Sea

“…The western Baltic Sea is a highly dynamic system (Siegel et al, 2005), influenced by the mainly wind-driven exchange with the more saline North Sea through the narrow Danish Streets and the less saline Baltic Proper (Feistel et al, 2008). As a consequence a salinity gradient from west to east occurs with the Darß Sill as a barrier for inflowing salty and oxygen-enriched bottom water (Fig.…”

“…1). Siegel et al (2005) combined ship measurements, satellite data and model simulations to show how the hydrographical conditions of the western Baltic Sea change under different wind conditions. Although the Darß Sill holds oxygen-rich bottom water back in the Mecklenburger Bay, seasonal hypoxias occur (HELCOM, 2009), as well in the Arkona Sea.…”

Optical Remote Sensing Applications in the Baltic Sea

“…The systematisation performed for the Pomeranian Bight was extended to the entire coast of the German state, to study the dynamical features and processes there. The derived features were related not only to the dominating wind directions but also to transitions between these directions (Siegel et al 2005b). The issued catalogue of processes supports the interpretation of monitoring data and the optimisation of the coastal monitoring programme of regional authorities.…”