Direction de la Technologie Marine et des Systèmes d'Informations
Département Informatique et Données Marines
Service Systèmes d'Informations Scientifiques pour la Mer (SISMER)
December 2001 - R.INT.TMSI/IDM/SISMER/SIS00-084
Medar-Medatlas Protocol Part I : Exchange format and quality checks for observed profiles
The MEDAR/MEDATLAS Consortium
The MEDAR/MEDATLAS consortium is composed of representatives of the National Oceanographic Data Centres and Designated National Agencies of the Mediterranean bordering countries, of specialists of objective analysis and of experts from the international organisations involved in oceanographic data management:
IFREMER/SISMER, INST. FRANÇAIS DE RECH. POUR L'EXPLOITATION DE LA MER, France (Catherine Maillard, Michèle Fichaut)
IEO, INSTITITUTO ESPANOL DE OCEANOGRAFIA, Spain (Maria-Jesus Garcia)
Participation of advising data centres (WDCA, MEDGOOS) and other countries data centres will be acknowledged.
1.Introduction to the MEDAR/MEDATLAS protocol 4
2.MEDATLAS FORMAT - Datasets organisation & identifiers 7
A group of historical stations was identified as a virtual cruise if they have been collected on board the same vessel during a specific time period. In that case it was possible to reconstruct the ship track for further checks. 8
The cruise duration should not exceed one year. If this were the case, the cruise was split into different legs between calls into ports. But it is not necessary to cut a cruise at the end of a year. 8
The usual number of profiles of the same type made is between 10 and 200, and the processing software is adapted to this order of magnitude. 8
In case of coastal repeated stations made with different ships, (not always identified), it is possible to identify the cruise by "Station X - year YYYY " or "Station X - Month YYYY" 8
4. Quality checks 23
Introduction to the MEDAR/MEDATLAS protocol
Context and overall objectives
Humankind has placed many pressures on the marine environment, particularly in the most recent decades. This has drawn attention to the urgent need to manage, in a sustainable way, the living and non-living resources of the ocean. This applies in particular to areas such as the Mediterranean and Black Seas whose ecosystem are delicately balanced. Long time series of many different physical, biological and chemical observations are required to assist in the establishment of a scientific basis for ocean management. MEDAR contributes to this process by ensuring the availability of long time series of observations of known quality and precision, including:
Dissolved Oxygen: deficiencies below the top layers, in the upper layers, which arise from eutrophication due to e.g., discharge of sewage, industrial, agricultural and aqua cultural effluents, can result in destruction of higher life forms, liberation of toxic forms of metals and pathology in living organisms.
Nutrients: changes in nutrients fluxes, whatever natural or introduced to the sea partly as a result of human activity (eutrophication), can alter primary production and the bio-diversity, and can directly affect aquaculture, fishing activity.
Temperature and Salinity: which are the primary indicators of climate variability and change permit the computation of geostrophic currents, and other derived parameters such as density of seawater and sound velocity, currently used in the off shore industry (oil prospecting, communication cable lay out, remote data transmission).
As expressed in several international workshops under the auspices of the Intergovernmental Oceanographic Commission (IOC) of UNESCO, these requirements are specially important in the Mediterranean and Black Sea context where, due to the narrow shelf and slope areas, the coastal zone environment has a strong interrelation with deep sea regions. The MEDAR/MEDATLAS project aims to ensure the archiving and availability of such parameters in order to improve the management of these areas..
This Protocol describes the common standards necessary to ensure the coherence and compatibility of archived data sets. It also provides a methodology to detect and eliminate the duplicated data sets, which is a major problem arising when historical data sets are compiled from various sources. In order to facilitate the detection of duplicated data, data are organised by country and by cruise and related to the national cruise catalogues.
This Protocol is based on 1) international standards from UNESCO/IOC and ICES built within the framework of the International Oceanographic Data and Information Exchange (IODE) and the Global Ocean Data Archaeology and Rescue (GODAR) programmes, and 2) the former protocols and experience gained in other MAST data management initiatives: the pilot MAST/MEDATLAS (MAS2-CT93-0074) project, MODB (MAS2-CT93-0075-BE) and MTPII/MATER in the Mediterranean Sea.
The list of core environmental parameters to rescue and safeguard in priority has been defined in a workshop held in Istanbul in May 1997 (1):