Combining ESGF Data node with its complementary data services at the NASA Center for Climate Simulation

Abstract:

The NASA Climate Model Data Service (CDS) and the NASA Center for Climate Simulation (NCCS) are collaborating to manage an Earth System Grid Federation (ESGF) node that distributes over 150 TB of climate model data in support of multiple ESGF projects; Climate Model Intercomparison Project (CMIP5), NASA observational data for model-data comparisons (obs4MIPs), reanalysis data (ana4MIPs) and downscaled NASA Earth Exchange Downscaled Climate Projections (NEX-DCP30) climate data. The purpose of ESGF is to improve collaboration among climate modelers and to extend access to these climate data to other scientific communities.

A complementary THREDDS server was set up to provide services that are not available through the ESGF data node but are of great interest to a broad user community. For example, the high spatial resolution of the downscaled NEX-DCP30 climate data attracts many GIS users who are interested in a slice/point time series subset. This cannot be done through ESGF but can be done through the complementary THREDDS server that is seamlessly linked to ESGF. Another example is the customized aggregation prepared for the complementary THREDDS service that provides access from the USGS Geo Data Portal (GDP). This access requires the aggregation of 23 models each containing 3 variables.

BioClim data (Biodiversity) in geotiff format have been published, becoming the first geotiff image files to be successfully published in ESGF. In order to make ESGF's Live Access Server (LAS) work with BioClim geotiff, we recompiled THREDDS with the USGS-CIDA geotiff-iosp plugin. The plugin adds the ability to access geotiff format with OPeNDAP through THREDDS. This enables LAS, which uses FERRET, to provide visualizations of the data. This technique was extended to provide LAS access to the NEX-DCP30 data.

Recently we have expanded the complementary server to cover NASA Global Modeling and Assimilation Office (GMAO) forecast and assimilation operational products in near real time. Future work includes incorporating Web Map Service (WMS), either when it is enabled in ESGF or through a standalone WMS viewer accessing the complementary server, to visualize ana4MIPs and obs4MIPs datasets, thereby providing georeferenced images of climate data stored as netcdf files. Use Cases for each of these projects will be presented.