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ICDC
CENIntegrated Climate Data Center ICDC

Photo: getty images/L. Calvetti

The ICDC Technical Concept

Technically, ICDC has two main components:

  1. An internal data server accessible from all KlimaCampus where climate data sets are being stored, made easily accessible through common formats, and continuously updated. Climate data are also being visualized and displayed in public through the CLISAP VIS expert.
  2. A web site and a data portal to the inside and outside world (e.g., ftp, THREDDS, OPeNDAP). The web site serves meta data to the members of the KlimaCampus and to the outside world. In collaboration with the CLISAP outreach, it provides information about climate variability such as climate indices. Web applications like THREDDS and Live Access Server provides easy data access.

1) Internal Data Server Concept

ICDC provides direct access via the file system on an internal data server accessible from all CEN/MPI Unix Workstations and Servers via /data/icdc. The data sets are stored on a storage connected to the server in an easily accessible file directory tree. In order to simplify the usage, data sets are provided through common formats like netCDF or ASCII. Meta data information to every dataset can be found on our content base, the ICDC website. Automatic scripts can provide regular data updates, weekly data backups save the collected data. There is a goal to integrate data sets from other sources of the KlimaCampus network.

2) Web Server Concept

The content base of our data center is the Content Management System FIONA. ICDC provides data access via a FTP server and the THREDDS data server. The Live Access Server (LAS) is used for visualizing data. ICDC provides separate data access to internal (inside our network) and external users due to different needs of these user groups and to different rights to spread data.

Content base FIONA

ICDC uses FIONA as a content base, where all information and links to downloads, visualizations and external references flow together. FINA is the Content Management System (CMS) from INFOPARK that is the standard at University of Hamburg. It is the 3rd CMS for ICDC. ICDC decided to replace the former used CMS TYPO3 due to the Due to the high maintenance requirements and replaced the CMS Plone due to a number of reasons mainly it was not userfriendly. Plone is the better choice for individual access management, but as the data are stored on a LAS/Thredds server and not on the web-server, this feature is not useful.

Data access via THREDDS / LAS

A THREDDS data server provides data access for scientific datasets, especially for geo-referenced data and offers two important remote data access protocols: Users can download datasets via your web browser through HTTP and use subsets of data without downloading the entire dataset with the help of OPeNDAP. THREDDS also creates virtual datasets through aggregation, so you can merge a chronological sequence of datasets to one and access it via OPeNDAP. The Live Access Server provides visualizations of geo-referenced data in netCDF format and via OPeNDAP, so that it can also visualize aggregations from THREDDS. LAS can also read (insitu) data from a SQL database, so that we can visualize many geo-referenced datasets including satellite, in situ and model data.