Preliminary Experiments of Four-Dimensional Data Assimilation

Abstract

Numerical experiments have been conducted to investigate methods of the four-dimen-sional data assimilation. After the satellite data are collected, an intermittent method of the four-dimensional data assimilation is applied, using the operational Northern Hemispheric Primitive Equation Model of the Japan Meteorological Agency. The response of the model to the inclusion of the satellite dataa is studied. The high frequency mode generated by the data insertion is well suppressed, but the low frequency mode is not completely filtered out. The impact of the satellite data seems to be acceptable in the extra tropics. However, the situation is different in the tropics; in some cases noises caused by the data insertion are not negligible in the assimilated field. The problem to suppress these noises in the tropics remains unsolved.