Transient properties of atmospheric circulation in two reanalysis datasets

LI L. Z. X. AND A. F. CARRIL

IPSL/TN

IPSL

Lugar: Paris, Francia; Año: 1998 p. 1 - 24

The transient behavior of the atmospheric circulation is examined in two reanalysis datasets provided respectively by NCEP (National Centers for Environmental Prediction, NOAA) and ECMWF (European Center for Medium-range Weather Forecasts). The time period for both datasets covers 1979-1993. The agreement between the two reanalyses is, in general, good in the Northern Hemisphere. But in the Southern Hemisphere, considerable discrepancies exist over the data-poor regions. The transient kinetic energy, the meridional transient flux of heat and angular momentum are about 20\% smaller in NCEP than in ECMWF. These differences are mainly due to the fact that transient events have smaller amplitude in NCEP than in ECMWF. However their time evolution and space pattern agree well between the two datasets.