G5NR Data Access Guide: Difference between revisions
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OPeNDAP is a data server architecture that allows users to use data files that are stored on remote computers with their favorite analysis and visualization tools. Opening an OPeNDAP file is as easy replacing the file name in the client software by an OPeNDAP URL. All G5NR collections that are provided by ftp/download-tool are also available on the OPeNDAP server | OPeNDAP is a data server architecture that allows users to use data files that are stored on remote computers with their favorite analysis and visualization tools. Opening an OPeNDAP file is as easy replacing the file name in the client software by an OPeNDAP URL. All G5NR collections that are provided by ftp/download-tool are also available on the OPeNDAP server | ||
https://opendap.nccs.nasa.gov/dods/OSSE/G5NR/Ganymed/7km | |||
===== [[Recipe: Fortran program as OPeNDAP client|Fortran client]] ===== | ===== [[Recipe: Fortran program as OPeNDAP client|Fortran client]] ===== | ||
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===== R ===== | ===== R ===== | ||
This example requires the [ | This example requires the [https://cran.r-project.org/web/packages/ncdf4/index.html ncdf4] and [https://cran.r-project.org/web/packages/rworldmap/index.html rworldmap] packages. | ||
<syntaxhighlight lang="rsplus"> | <syntaxhighlight lang="rsplus"> | ||
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> jm <- 361 | > jm <- 361 | ||
> lm <- 72 | > lm <- 72 | ||
> nc <- nc_open(" | > nc <- nc_open("https://opendap.nccs.nasa.gov:9090/dods/OSSE/GEOS-5.12/BETA9/0.5000_deg/inst/inst01hr_3d_T_Cv") | ||
< t <- ncvar_get(nc,"t",start=c(1,1,1,37),count=c(im,jm,lm,1)) | < t <- ncvar_get(nc,"t",start=c(1,1,1,37),count=c(im,jm,lm,1)) | ||
> str(t) | > str(t) | ||
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===== IDV ===== | ===== IDV ===== | ||
[ | [https://www.unidata.ucar.edu/software/idv/ IDV] is an OPeNDAP tool that can access and display the nature run data. In our OPenDAP server, all files are time aggregated, so they appear as a single dataset for each location. | ||
This is an example to open and display the field 'T' (air temperature) from the collection 'inst01hr_3d_T_Cv'. The OPenDAP URL for this dataset is | This is an example to open and display the field 'T' (air temperature) from the collection 'inst01hr_3d_T_Cv'. The OPenDAP URL for this dataset is https://opendap.nccs.nasa.gov:80/dods/OSSE/GEOS-5.12/BETA9/0.5000_deg/inst/inst01hr_3d_T_Cv. The following steps are valid for IDV version 5.0u1 running on a Linux desktop. | ||
From the 'Dashboard' panel | From the 'Dashboard' panel | ||
Revision as of 10:23, 9 April 2019
For questions or comments please send an email to g5nr at lists dot nasa dot gov.
G5NR background
The GEOS-5 Nature Run (Ganymed release) is a 2-year global, non-hydrostatic mesoscale simulation for the period 2005-2006. In addition to standard meteorological parameters (wind, temperature, moisture, surface pressure), this simulation includes 15 aerosol tracers (dust, seasalt, sulfate, black and organic carbon), O3, CO and CO2. This model simulation is driven by prescribed sea-surface temperature and sea-ice, daily volcanic and biomass burning emissions, as well as high-resolution inventories of anthropogenic sources.
GEOS-5 files are generated with the Network Common Data Form (NetCDF-4) library, which uses Hierarchical Data Format Version 5 (HDF-5) as the underlying format. NetCDF-4 is an open-source product of UCAR/Unidata (https://www.unidata.ucar.edu/software/netcdf/) and HDF-5 is developed by the HDF Group (http://www.hdfgroup.org/). One convenient method of reading GEOS-5 files is to use the netCDF library, but the HDF-5 library can also be used directly.
Each GEOS-5 file contains a collection of geophysical quantities that we will refer to as "fields" or "variables" as well as a set of coordinate variables that contain information about the grid coordinates. The variables as well as the complete structure of the file can be quickly listed using common utilities like ncdump or h5dump.
For more details about File Spec, please see File:G5NR-Ganymed-7km FileSpec-ON6-V1.0.pdf.
For model configuration, please see File:GMAO-OfficeNote-5-V1-22Oct2014.pdf.
Download data files
Global data
FTP
HTTPS
Data subsets
Download tool
Read downloaded data files
Fortran program
C program
Python script
Matlab script
IDL script
Panoply
OPeNDAP access
OPeNDAP is a data server architecture that allows users to use data files that are stored on remote computers with their favorite analysis and visualization tools. Opening an OPeNDAP file is as easy replacing the file name in the client software by an OPeNDAP URL. All G5NR collections that are provided by ftp/download-tool are also available on the OPeNDAP server
https://opendap.nccs.nasa.gov/dods/OSSE/G5NR/Ganymed/7km