The Climate Prediction Center’s (CPC) daily rainfall data for the entire world, 1979 – present & 50-km resolution, is one of the few high quality and long term observation-based rainfall products. Data is available at CPC’s ftp site. However, it is a lot of data and there is no software to analyze and visualize the data.
Some issues with size/format of the CPC data:
- too many files (365/366 files per year * 34 years, separate folder for each year)
- each file has 360 rows and 720 columns
- file naming conventions have changed over time – one format prior to 2006 and couple of different formats afterwards
- file formats have changed over time – gzipped files prior to 2008 and plain binary files afterwards
- downloading multiple files simultaneously from the CPC ftp site, using wget, does not seem to work properly
- there is no software/code readily available to easily process/visualize the data
The R package `raincpc` makes life easier by providing functionality to download and process the data from CPC’s ftp site. Some features of this new package are:
- Data for anytime period during 1979-present can be downloaded and processed
- Just two functions required: one to download the data (`cpc_get_rawdata`) and another to process the downloaded data (`cpc_read_rawdata`)
- Making spatial maps using the processed data is easy, via ggplot
Here are some examples on how to obtain and visualize the data – https://github.com/RationShop/raincpc
Below are the relevant CRAN and GitHub sites:
Please let me know if you find any errors or if you have any comments or suggestions.