Geoscience Reference
In-Depth Information
3. Results
Previous studies have documented the weakness of the humidity in the
reanalyses, particularly, at the lower troposphere. Zhang
14
compared the
monthly humidity from the NCEP/NCAR and ECMWF 40-year reanalyses
with the station observations in the East China in 1990s, and he found that
the humidity in both the NCEP/NCAR and ECMWF 40-year reanalyses in
the lower troposphere is much larger than that from the station observation,
concurrent with a cold bias in the air temperature. Tian
et al.
15
identified
that the lower-troposphere moisture and temperature structure related to
MJOismuchlesswelldefinedinNCEPthaninAIRSinthePacificand
Indian Oceans. In Fig. 1, we compare the 10-day mean humidity at 1000 hPa
in May for 2003-2006 from AIRS observations with the NCEP/NCAR
reanalysis. Overall, the magnitude in NCEP/NCAR reanalysis is larger
than those of AIRS observations. In the SCS region, the moisture maximum
in the AIRS observation locates in the ocean but in the NCEP/NCAR
Fig. 1. 10-day mean specific humidity from AIRS observations (left panels) and from
the NCEP/NCAR reanalysis (right panels) at 1000 hPa for 2003-2006 in unit of g/kg.
Shaded areas denote the values lager than 17 g/kg for AIRS and 19 g/kg for NCEP/
NCAR data.
