Journal of the Meteorological Society of Japan: Vol. 66, No. 2, pp. 261-276, 1988.
Dynamic Normal Mode Initialization for a Limited-area Model
By Takehiko Satomura
Centre National de Recherches Meteorotogiques/EERM, 31057 Toulouse CEDEX, France
(Manuscript received l4 November 1987. in revised form 29 January 1988)
Abstract
The dynamic normal mode initialization scheme (DNl) proposed by Sugi is applied to a limited-area model. Performance of two integration schemes for DNl is examined, and it is shown that Okamura's time integration scheme is inefficient and a backward implicit scheme is appropriate for DNI applied to the limited-area model. All physical processes can be included in the integration cycle of DNl. Horizontal wind and precipitation rate are compared using a control forecast, a forecast with the nonlinear normal mode initialization (NMI), and with DNl. The deformation of horizontal wind near the mountains is reconstructed by DNl better than by NMI. The area-averaged precipitation is not largely improved by DNl, but the rms error of the precipitation from the control forecast is smaller in DNl than in NMI in the first three hours.