13 November 2015

GRIB Practical Exercise 2: Test Spin

NASA's Panoply Data Viewer provides an easy-to-use way to open up and explore many earth science datasets .  It recognizes different flavors of GRIB, HDF and NetCDF and allows you to plot or view data without knowing specifics of a file.  If you haven't already done so, install it now.



Just for fun, I downloaded a two-month time-series of a spatial subset of ds083.2, FNL, for 20141201 through 20150131.  Because I don't want to open up each file individually, I used the concatenation technique I mentioned in What is GRIB2?
cat fnl*spasub* > movie.grib2
244 files can be merged into one file for movie-making mayhem.
Open up the Panoply application and select your data file(s) by browsing in the pop-up window.
Then select the variable of interest.  I selected 'Geopotential _height_isobaric'.  Then I selected the 50000 Pa isobaric surface, also known as (aka) the 500 mb surface aka 'half-height of the atmosphere'.

Set up your Panoply window for optimal viewing. In this case I clicked on the Map tab and selected the 'Equirectangular (Regional)' Projection from the menu.

Then click on the Data tab and enable 'Always fit to data'.

Go back to the Array(s) tab, and click on an arrow in the 'GRIB reference time' to step forward or backward.  You just made a movie using binary GRIB2 files.

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