Sample analysis file from MERRA (Modern-Era Retrospective analysis for Research and Applications), produced by NASA (http://gmao.gsfc.nasa.gov/merra/). This contains historical analysed fields (i.e. output from data assimilation) from this global numerical weather prediction modeling system. - Dimensions: 144×288 grid-points in the horizontal with a global coverage on a 1.25 x 1.25 degree geographical grid. There are 42 vertical levels from 1000hPa to 0.1hPa. - There are 8 time-points, representing regular three-hourly snapshots from 2013-06-01 00:00:00 UTC. - There 11 variables with these four dimensions, including dynamical fields (wind components, pressure, temperature, vorticity, geopotential height) and composition (relative humidity, liquid water and ice mixing ratios, ozone mixing ratio).