Compilation of a quality-controlled database of biological and chemical oceanographic parameters in the Central Mediterranean Sea

Abstract The EU-MAST/MEDAR/MEDATLAS II project (Mediterranean Data Archeology and Rescue of temperature, salinity and bio-chemical parameters, 1998-2001) provided the most updated and comprehensive data set and climatological atlas of physical, biological and chemical oceanographic parameters for the Mediterranean and Black Sea. The MEDAR/MEDATLAS II is a distributed data-management structure made up of the NODC/DNA from 20 countries, four regional data centres (in charge of data compilation in the Eastern, Central, and Western Mediterranean and the Black Sea, respectively) and a global assembling centre (responsible for the overall integration). These centres have strengthened the IOC/IODE network at national and regional level, enhancing the overall capacity in data rescue and validation. The multidisciplinary hydrographic data set, globally assembled, was checked for quality by common compatible and coherent procedures, based on international standards. The validation process, fully implemented for temperature, salinity, dissolved oxygen, nitrate, phosphate, and silicate, was extended to other biological and chemical parameters, which include alkalinity, ammonium, chlorophyll-a, nitrite, pH, total phosphorus and total nitrogen. New broad-range check values in the sub-domains� discretisation of the Central Mediterranean were defined. The global analysis of the biological and chemical core parameters defined very wide ranges at the surface, rather wide ones for the intermediate layer, while the ranges are narrow in the deep layer. The statistical results obtained here could be used to improve data management practices, by providing trustworthy intervals to substantiate studies on spatial-temporal variations of selected physical, biological and chemical properties over the past 80 years.