Abstract: We reexamine the coupled lower boundary condition of Chen and Trenberth and show that for consistency the vertical velocity should be corrected from the mountain surface to the lowest computational level. This correction ...

Abstract: AbstractThe next generation of advanced high-resolution sensors in geostationary orbit will gather detailed information for studying the Earth system. There is an increasing desire to perform observing system simulation ...

Abstract: The establishment of stationary waves in the Northern Hemisphere winter is investigated using stationary and time-dependent linear primitive equation models. Confirming the results of Nigam and Lindzen, we find that small ...

Abstract: Ultralong Rossby waves (low zonal and meridional wavenumbers on the sphere) have been studied for many years. Extensive observational evidence tends to identify these waves with the gravest normal modes of the atmosphere. ...

Abstract: The maximum-likelihood method for estimating observation and forecast error covariance parameters is described. The method is presented in general terms but with particular emphasis on practical aspects of implementation. ...

Abstract: The implications of using different control variables for the analysis of moisture observations in a global atmospheric data assimilation system are investigated. A moisture analysis based on either mixing ratio or specific ...

Abstract: The implementation of a technique for locating programming errors in shallow-water codes, establishing the correctness of the code, and assessing the performance of the numerical model under various flow conditions is ...

Abstract: General circulation models are unable to resolve subgrid-scale moisture variability and associated cloudiness and so must parameterize grid-scale cloud properties. This typically involves various empirical assumptions and ...

Abstract: The characteristic Rossby frequency is defined for a fixed zonal wavenumber perturbation as the variational integral of the Rayleigh-Ritz method. It is a measure of the time scale of the disturbance. For a disturbance which ...

Abstract: he real-time treatment of interactive, realistically varying aerosols in a global operational forecasting system, as opposed to prescribed (fixed or climatologically varying) aerosols, is a very difficult challenge that ...