README.md

In dlebauer/cpcRain: cpcRain

cpcRain

R code to download and analyze global precipitation data from the Climate Prediction Center (CPC)

• Spatial Coverage: Global (mostly land areas)
• Temporal Coverage: 1979/1/1 - present
• Spatial Resolution: 0.5 degrees lat-lon (~ 50 x 50 km)
• Temporal Resolution: daily

Global Precipitation Data from Climate Prediction Center (CPC)

Hydrological and climatological studies sometimes require rainfall data over the entire world for long periods of time. The Climate Prediction Center's (CPC) daily data, from 1979 to present, at a spatial resolution of 0.5 degrees lat-lon (~ 50 km at the equator) is a good resource. This data is available at CPC's ftp site (ftp://ftp.cpc.ncep.noaa.gov/precip/CPC_UNI_PRCP/GAUGE_GLB/). However, there are a number of issues:

Issues with obtaining data: there are too many files (365/366 per year * 34 years, separate folder for each year) file naming conventions have chnaged over time, one format prior to 2006 and couple of different formats afterwards * downloading multiple files simultaneously from the CPC ftp site does not seem to work properly.

Issues with processing data: file formats have changed over time, gzipped files prior to 2008 and binary files afterwards files are in binary format and there no software/code readily available to process/plot the data

R code

The following R code makes the task of downloading the above data and subsequent processing and plotting very easy. "cpc_lib.R" - library of functions to download and process/reformat the data "cpc_analyze.R" - invokes the functions from the above library and demonstrates how to obtain and plot the data for Hurricane Sandy (2012).

Note

Files prior to 2008 are in gzipped format and the download time for individual files is short, compared to the files from 2009 onwards. These 2009+ files are larger is size and take longer times.

dlebauer/cpcRain documentation built on May 15, 2019, 9:14 a.m.