Pub. date: 2008 | Online Pub. Date: April 25, 2008 | DOI: 10.4135/9781412963893 | Print ISBN: 9781412958783 | Online ISBN: 9781412963893| Publisher:SAGE Publications, Inc.About this encyclopedia
Climatic Data, Reanalysis
REANALYSIS CLIMATIC DATA is a long-term consistent climatic dataset. The dataset is produced from a state-of-the-art data assimilation system combining both past observations from various sources and short-range forecasts from simulation models to obtain the best statistical estimate of the state of the atmospheric flow. For numerical weather prediction (NWP), the observations from sources irregularly distributed in space and time are analyzed in a unified and consistent manner with the aid of computer models to describe the state and evolution of the atmosphere. Such a procedure combining different data is generally denoted as “numerical analysis” or “data assimilation” and reanalysis climatic data is produced from a state-of-the-art data assimilation system. Determining the initial conditions of the state of the atmosphere for forecast models is a key process in NWP, whose results heavily depend on these initial conditions. The equations of the motion of the atmosphere are integrated forward from predetermined ...