INVESTIGATION OF TIME EVOLUTION OF SOIL MOISTURE FROM INITIAL CONDITIONS WITH SYSTEMATIC BIASES IN DYNAMICAL SEASONAL PREDICTION WITH JMA/MRI ATMOSPHERIC GCM

Abstract

 The time evolution of soil moisture from initial conditions given as a lower boundary condition in dynamical seasonal prediction was investigated with the Japan Meteorological Agency/Meteorological Research Institute Atmospheric General Circulation model. Both dynamical seasonal predictions from the initial conditions and historical simulations were performed and their differences in soil moisture in the second layer of a land-surface submodel were compared. The differences become smaller as an elapsed time increase in most regions except for the northern hemispheric mid- and high latitudes and northern Africa for the initial start of November, and Northern Africa to Pakistan, Eurasian inlands, and coastal land areas along the Antarctic Ocean for the initial start of May. A first-order Markov model for time evolution of soil moisture was introduced and examined with three simplified sensitivity numerical tests.