This subdirectory is for the NASA-CASA (Version 2) land surface CO2 flux data.
The following data are included:

1. NASA-CASA 3-hourly NEE data AMES.casa.3hr.1x1.25.2009.nc and AMES.casa.3hr.1x1.25.2010.nc.
   The resolution is 1.25x1 degrees. Unit is kg C/m^2/s. The data format is netCDF.

2. NASA-CASA cropland harvest emission data casa_dist.1x1.25.2009.nc and casa_dist.1x1.25.2010.nc.
   The resolution is 1.25x1 degrees. Unit is kg C/m^2/s. The data format is netCDF. It does not
   have seasonal variation. 

3. NPP.0.5x0.5.monthly.200901-201012.bin, the NASA-CASA monthly NPP data.
   The data format is direct access unformatted binary data. A Fortran program
   read.NPP.f is provided to read the data. Resolution is 0.5x0.5 degrees.
   Unit is kg C/m^2/s.

4. Rh.0.5x0.5.monthly.200901-201012.bin, the NASA-CASA monthly respiration data.
   The data format is direct access unformatted binary data. A Fortran program
   read.Rh.f is provided to read the data. Resolution is 0.5x0.5 degrees.
   Unit is kg C/m^2/s.

5. casa_dist.0.5x0.5.2009-2010.bin, the NASA-CASA crop harvest emission data for 2009 and 2010.
   The data format is direct access unformatted binary data. A Fortran program
   read.dist.f is provided to read the data. Resolution is 0.5x0.5 degrees.
   Unit is kg C/m^2/s.
   
6. FPAR.0.5x0.5.2009-2010.bin, the NASA-CASA monthly FPAR data.
   The data format is direct access unformatted binary data. A Fortran program
   read.FPAR.f is provided to read the data. Resolution is 0.5x0.5 degrees.
   Unit is fraction.

The data format is netCDF. It can be read, display or write out with IDL or grads. The grids,
unit, and timing of the data can be found by using "ncdump" command.

The original NPP and Rh of the NASA-CASA are monthly data and in 0.5x0.5 resolution.
The data are interpolated to a 1.25x1 resolution, and the unit is changed from g C/m^2/month
to kg C/m^2/s. We produced the 3-hourly NEE data from the monthly NPP and Rh data using
the method of Olsen and Randerson (2004, JGR). The 3-hrly surface air temperature (T2m) and 
short wave radiation reaching the surface of the MERRA analysis data are used for producing
the 3-hrly NEE.



Contact Zhengxin.Zhu-1@nasa.gov if you have any questions about how to read the data.