Diurnal variability of turbidity and light attenuation in the southern North Sea from the SEVIRI geostationary sensor

This study follows up on the successful feasibility study of Neukermans et al. (2009) for mapping suspended matter in turbid waters from the SEVIRI sensor on board the METEOSAT geostationary weather satellite platform. Previous methodology is extended to the mapping of turbidity. T, and vertical attenuation of photosynthetically active radiation (PAR), K-PAR. The spatial resolution of the SEVIRI products is improved from 3 km x 6.5 km to 1 km x 2 km using the broad high resolution visual band. The previous atmospheric correction is further improved and the uncertainties on marine reflectance due to digitization are considered. Based on a two year archive of SEVIRI imagery, available every 15 min, the diurnal variability of T and K-PAR is investigated during cloud free periods and validated using half-hourly T and K-PAR data obtained from a system of moored buoys (SmartBuoys) in the southern North Sea. Based on numerous match-ups, 80% of SEVIRI derived T and K-PAR are within 53% and 39% of SmartBuoy T and K-PAR, respectively. Results further show that on cloud free days, the SEVIRI T and Km signals are in phase with the SmartBuoy data, with an average difference in the timing of the maximum T and K-PAR of 11 min and 23 min, respectively. It is concluded that diurnal variability of T and K-PAR can now be mapped by remote sensing offering new opportunities for improving ecosystem models and monitoring of turbidity. Limitations of the current SEVIRI sensor and perspectives for design of future geostationary sensors and synergy with polar orbiting satellites are discussed. (C) 2012 Elsevier Inc. All rights reserved.