Post on 19-Dec-2015
The Effect of Vertical Resolution on Zonal
Wind Stress in AMIP Runs
Glenn.White@noaa.gov
An evaluation of
monthly means
from Suru Saha’s AMIP runs
with observed SST 1979-2001 PRX
28 versus 64 levels
Validation NCEP Reanalyses
CDAS, NCEP2
FSU Stresses 1978-2000
SOC flux climatology 1980-93
SOC 1980-83
Zonal mean
Ocean
5S-5N 1980-93
SOC
5S-5N
Pacific FSU
1980-93 SOC
Time-mean
Us
Pacific FSU
1979-2000
Time-mean zonal wind stress
Annual Cycle
1980-93
Pacific
SOC
FSU
CDAS
NCEP2
28 levels
64 levels
28 levels-NCEP2
64-NCEP2
64-28 levels
CDAS-NCEP2
Time-mean zonal wind stress 1980-93 SOC
Magnitude of systematic difference
CDAS
NCEP2
CDAS-SOC
NCEP2-SOC
28 levels
64 levels
28 levels minus SOC
64-SOC
Systematic difference from
FSU 1980-93 Mean
Tropical Pacific
JJA 1980-93 Time mean zonal wind stress
FSU
28
64
JJA 1980-93 Time mean zonal wind stress
SOC
CDAS
NCEP2
28-FSU
64-FSU
64-28JJA 1980-93 Time mean zonal wind stress
FSU-SOC
FSU-NCEP2
CDAS-NCEP2
JJA 1980-93 Time mean zonal wind stress
Anomaly correlation with NCEP2
28
64
CDAS
The reanalyses correlate better in time with FSU stresses than the AMIP runs, after the time-mean annual cycles are removed.
Monthly anomalies 1979-2000
Pacific
Anomaly correlation with FSU--Pacific
CDAS
NCEP2
28 levels
64 levels
Merid. Wind Stress
CDAS
NCEP2
28 levels
64 levels
Anomaly correlation with FSU merid. Wind stress
1979-2000
Difference in anomaly correlation with FSU
28 – NCEP2
64-NCEP2
64-28
FSU
Standard deviation of monthly anomalies
28 levels
64 levels
1979-2000
28-FSU
64-FSU
64-28
Difference in standard deviation
Standard deviation of monthly anomalies
1979-2000
CDAS
NCEP2
CDAS-FSU
NCEP2-FSUCDAS-NCEP2
1979-2000
64 levels do not produce better zonal wind stress than 28 levels.
Reanalyses display more agreement with SOC, FSU than AMIP runs.
64 level AMIP run too strong easterly stress in JJA, too strong westerly stress in JFM.