HIND_CTRL(uten 2005-2007) Z700 anomaly Rank histogram

Z700 anomaly Rank histogram at global, NAtl(20-70N, 110W-40E) and WNPac(20-70N, 110E-180)
ERA5 as observation data.
Rank histogram is ranking frequency of observation data with ensemble members. 
Histogram all flat -> good ensemble distribution.
Large at most right bin -> model members are overestimate.
Large at most left bin  -> model members are underestimate.
Bell shape -> model simulation is too diverse.
Inverted bell shape -> model simulation is too concentrated.