Information for pair0046: Mean daily relative humidity near surface (.995 sigma level) on a 144x73 grid (2.5 degree) of day 50 and day 51 of year 2000. x: year 2000, day 50 y: year 2000, day 51 units: % Data source: http://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.surface.html ground truth: x --> y