CMAP
Contents
CMAP¶
Overview¶
The CPC Merged Analysis of Precipitation (CMAP) includes monthly and pentad global gridded precipitation means. It has a standard version and one enhanced with NCEP Reanalysis. CMAP covers from 1979 to near the present on a global grid at 2.5 degree latitude x 2.5 degree longitude resolution. For more information you can check the original data source on the NOAA Physical Sceince Laboratory (PSL) website and the UCAR climate data guide for a review of the dataset.
Data download¶
The original data is created by NOAA Climate Prediction Center (CPC) and it is in ascii format; we download a netcdf version from PSL. For this reason the PSL data is updated irregularly, following updates at CPC.
The download script uses wget. It can be run as follows,
$ ./cmap.sh <file> <subset>
where enh for enhanced and std for standard.
Data location¶
We’ve downloaded the CMAP dataset to:
/g/data/ia39/aus-ref-clim-data-nci/cmap/data
There are two sub-folders:
enh for enhanced monthly data:
precip.mon.ltm.nc: enhanced long term monthly mean, derived from years 1981 to 2010precip.mon.mean.nc: enhanced monthly mean from 1979/01 to 2021/03precip.pentad.mean.nc: enhanced pentad mean from 1979/01 to 2016/12/27
std for standard monthly data:
precip.mon.ltm.nc: standard long term monthly mean, derived from years 1981 to 2010precip.mon.mean.nc: standard monthly mean from 1979/01 to 2021/03precip.pentad.mean.nc: standard pentad mean from 1979/01 to 2016/12/27
The update_log.txt file keeps track of remote and local updates to files.
The previously downloaded version is kept for reference in the previous_version sub-folders.
License¶
Unknown.
Data citation¶
Unknown.
References¶
Xie P and Arkin PA (1997): Global precipitation: A 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs. Bulletin of the American Meteorological Society, 78, 2539-2558. https://doi.org/10.1175/1520-0477(1997)078<2539:GPAYMA>2.0.CO;2
Huffman GJ, Adler RF, Arkin P, Chang A, Ferraro R, Gruber A, Janowiak J, McNab A, Rudolf B, and Schneider U (1997). The Global Precipitation Climatology Project (GPCP) combined data set. Bulletin of the American Meteorological Society, 78, 5-20. https://doi.org/10.1175/1520-0477(1997)078<0005:TGPCPG>2.0.CO;2
Acknowledgement¶
If you acquire CMAP Precipitation data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as the following in any documents or publications using these data:
“CMAP Precipitation data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA,
from their Web site at
Author note¶
We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the CMAP Precipitation data set freely available online in the future. Thank you!
Assistance¶
For assistance with CMAP data on NCI, open a new issue at https://github.com/aus-ref-clim-data-nci/CMAP/issues