The EFDC+ code has been upgraded to allow export of NetCDF-CF (NetCDF- Climate and Forecast) formatted data. This development has been conducted with the goal of providing EFDC+ output that can be read and displayed on web servers.
According to the UNIDATA User Guide the Network Common Data Form (NetCDF) software was originally intended to create, access, and share array-oriented data in a form that is self-describing and portable. These deal with a variety of data types that encompass single-point observations, time series, regularly-spaced grids, and satellite or radar images.
The NetCDF software functions as an I/O library, that can be accessed from different programming languages such as C, FORTRAN, Fortran 90, C++, Java, Perl, Python, and other languages for which a NetCDF library is available. The library stores and retrieves data in self-describing, machine-independent datasets. Each NetCDF dataset can contain multidimensional, named variables (with different types that include integers, reals, characters, bytes, etc.), and each variable may be accompanied by ancillary data, such as units of measure or descriptive text. The interface includes a method for appending data to existing NetCDF datasets in prescribed ways, functionality that is not unlike a (fixed length) record structure. However, the NetCDF library also allows direct-access storage and retrieval of data by variable name and index and therefore is useful only for disk-resident (or memory-resident) datasets.
NetCDF is designed to:
• Facilitate the use of common datasets by distinct applications.
• Permit datasets to be transported between or shared by dissimilar computers transparently, that is, without translation.
• Reduce the programming effort usually spent interpreting formats.
• Reduce errors arising from misinterpreting data and ancillary data.
• Facilitate using the output from one application as input to another.
• Establish an interface standard that simplifies the design of new software for accessing geoscience data.
The new version of EFDC+ is able to export the native output in NetCDF-CF format for Windows and Linux. EE_Explorer, the pre- and post-processor for EFDC+ can also convert EFDC *.OUT files to netCDF .nc files, including the derived WQ parameters. EFDC+ currently exports 44 parameters to NetCDF format as listed at the end of this document.
EFDC+ for EE10, exports the NetCDF files at the same interval that it produces the EFDC Model linkages files, which is set in the tab for Timing and Linkage | Linkage | NetCDF.
The main configuration for NetCDF output is in the EFDC_Exlporer Linkage | NetCDF tabs as shown in Figure 17. Here the user can turn on netCDF output by checking the Activate NetCDF Output checkbox. The user may select the level at which the NetCDF data is compressed with the Compression setting. This can range from 1, no compression, to 9 for maximum compression, but is recommended by UNIDATA to be set to 2 for the best balance between file size and speed.
The user may also select to Use Velocity Rotation. If this option is checked, the velocity field is rotated to true east and true north and if not checked then there is no rotation to true east and true north.
