ECMWF Re-Analysis Project ERA-Interim
Over the past decade, reanalyses of multi-decadal series of past observations
have become an important and widely utilized resource for the study of
atmospheric and oceanic processes and predictability. ECMWF has in the past
produced three major reanalyses: FGGE, ERA-15 and ERA-40.
ECMWF is currently producing ERA-Interim, a new global reanalysis of the
data-rich period since 1989. The ERA-Interim system is based on a recent release
of the Integrated Forecasting System (IFS Cy31r2) containing many improvements
both in the forecasting model and analysis methodology. ERA-Interim reanalysis
is expected to catch up with operations in late 2008. The reanalysis will then
be continued in near-real time with the same system in order to support climate
monitoring.
ERA-Interim has progressed beyond the end of ERA-40. After completion of the
first four years it was decided to revise the configuration of the system and to
rerun the initial segment. Other shorter reruns for later periods have been
completed as needed for technical reasons. The ERA-Interim archive is more
extensive than that for ERA-40, e.g the number of pressure levels is increased
from ERA-40's 23 to 37 levels and additional cloud parameters are included.