The figure shows sensitivities of Intra-ensemble variance for R (left) and S
(right) ensemble simulations. From top to bottom are GFS simulations
with the land surface model configuration of NOAH, OSU and NOAHX, respectively.
The experiment design is described as follows.
Atmospheric GCM: GFS T62 L64 (as in NCEP operation of seasonal forecast)
Land Surface Model (LSM) configurations:
OSU: OSU LSM (as in NCEP operation of seasonal forecast)
Noah: Noah LSM
NoahX: Noah LSM, initialized from Noah cycled Global Data Assimilation System
(GDAS)
Simulation period: 1994/06/01 ~ 1994/08/31
Initial conditions: CPC AMIP, using OSU
Three ensemble experiments (each with 16 members): W, R, S
W simulations: W1: establish a time series of surface conditions;
W2-W16: repeat without writing out land
variables
R simulations: each ensemble member given the same time series of
all land prognostic
states from W1
S simulations: each ensemble member given the same deep soil
moisture from W1