Quality Assurance

 

Home page
Project
Participants
Cruise Inventory
National Data Sets
Regional Data Assembling and Quality  Checks
Global Data Assembling
Observed Data
Climatological Data
Quality Assurance
Formats & Codes
Documentation
News, Meetings
IMPACTS Cluster
Links
CD-Rom Database

1. QUALITY ASSURANCE FOR OBSERVED DATA

Methodology

All the data are first reformatted at a common unique format : the auto descriptive (ASCII) MEDATLAS format which include information on the experimental conditions when available (meta-data). 

MEDATLAS FORMAT Description & Codes 

Parameter codes, names and units

The reformatted data are then submitted to  automatic/objective and visual/subjective checks according to the International recommendations from IOC, MAST and ICES. These checks are performed on each profile separately and also on profiles grouped by cruises. As a result, a quality flag is assigned to each numerical value. In case of outlier on recent data sets, the originator is contacted to validate/correct/eliminate the value.

The list of checks is detailed in the MEDATLAS protocol  developed in this task  under the co-ordination of  ICES (http://www.ices.dk/).  

 

Regional Adjustments of the checks

The principle of the QC of any parameter is to compare the observations with the available statistics of the same parameter. These statistics vary from a region to another, and the checks are adjusted accordingly..

1.  Broad band Checks

All the control reference values are adjusted in sub-areas to take into account the local diversity.

mapmedi0701.gif (26813 octets)


Geographical Limits of the QC sub-regions

2.  Climatological Checks

Temperature and Salinity : 1x1 Averaged MEDATLAS 97 Climatology (Zip file, 322 KO - if difficulty to unzip, download power archive freeware)
Bio-chemical parameters : Levitus 98

Implementation

The Quality checks are performed in REGIONAL QUALIFICATION CENTRES (Task II)

Western Basin - IEO Data Centre (http://www.ieo.es/medar/)
Central Basin - INOGS Data Centre (http://doga.ogs.trieste.it/medar)
Eastern Basin - NCMR/HNODC (http://hnodc.ncmr.gr/proj_med2.html)
Black Sea - RIHMI-WDC (http://www.meteo.ru/nodc/project/project.htm)

2. QUALIFICATION CENTRES FOR GRIDDED PRODUCTS

The gridded data are also controlled visually by the experts of the regional and national data centres. Further qualification methods are developed:

Temperature and salinity climatologies - ISAO - (http://www.isao.bo.cnr.it/)
Bio-chemical climatologies - ENEA - (http://estaxp.santateresa.enea.it/www/ec/medar.html)

 

 

[bottom.htm]