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Extracting NOAA sea surface temperatures with ncdf4

I’ve written previously about some example R scripts I created to extract sea surface temperature data from NOAA’s Optimum Interpolated Sea Surface Temperature products. If you want daily global sea surface temperatures on a 0.25×0.25° grid, they gather those into 1-year files available at http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.oisst.v2.highres.html. If you want weekly average SST values on a 1×1° grid, you can get those back to 1981 at http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.oisst.v2.html. If you just want a smaller file for a single day on the 0.25×0.25° grid, you can find those at http://www.ncdc.noaa.gov/sst/griddata.php.

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ncdf4 R package binaries for Windows

David Pierce has made available a pre-packaged Windows binary version of his ncdf4 package for R. Go to his ncdf page to download the zip file you need. The current file at the time of this writing is ncdf_1.8.1.zip.

http://cirrus.ucsd.edu/~pierce/ncdf/

After downloading the zip file to your Windows computer, you can install this R package most quickly by opening a Rgui.exe window, then going to the menus and choosing Packages>Install package(s) from local zip files…, select the zip file you downloaded, and hit Open to have R install the package.

To use the package in R, you must run a 32-bit … Continue Reading

Extracting sea surface temperatures from NOAA’s OISSTv2

Update, 2015-11-30 It appears that NOAA has gone through and upgraded all of the OISST files to the newer version of the NetCDF file format. As a result, the functions outlined in this post don’t work any longer. Instead, see the updated functions in my newer post, http://lukemiller.org/index.php/2014/11/extracting-noaa-sea-surface-temperatures-with-ncdf4/. The concepts are the same as described here, but the newer functions use the ncdf4 package to access the newer NetCDF file format.

Sea surface temperatures

NOAA’s Physical Sciences Division produces a global map of weekly averaged sea … Continue Reading