Search
CSV
RISFour-Dimensional Variational Data Assimilation with Digital Filter Initialization
Publisher: American Meteorological Society
Abstract: A four-dimensional variational (4DVAR) data assimilation problem may be constrained so that the solution closely fits the observations but is balanced. In this way, the processes of data analysis and initialization are ...
Temporal Accumulation of First-Order Linearization Error for Semi-Lagrangian Passive Advection
Publisher: American Meteorological Society
Abstract: The tangent linear model (TLM) is obtained by linearizing the governing equations around a space- and time-dependent basic state referred to as the trajectory. The TLM describes to first-order the evolution of perturbations ...
Four-Dimensional Data Assimilation and Balanced Dynamics
Publisher: American Meteorological Society
Abstract: The problem of spurious excitation of gravity waves in the context of four-dimensional data assimilation is investigated using a simple model of balanced dynamics. The model admits a chaotic vortical mode coupled to a ...
A Low-Order Model Investigation of the Analysis of Gravity Waves in the Ensemble Kalman Filter
Publisher: American Meteorological Society
Abstract: The behavior of the ensemble Kalman filter (EnKF) is examined in the context of a model that exhibits a nonlinear chaotic (slow) vortical mode coupled to a linear (fast) gravity wave of a given amplitude and frequency. It ...
Is Missing Orographic Gravity Wave Drag near 60°S the Cause of the Stratospheric Zonal Wind Biases in Chemistry–Climate Models?
Publisher: American Meteorological Society
Abstract: early all chemistry?climate models (CCMs) have a systematic bias of a delayed springtime breakdown of the Southern Hemisphere (SH) stratospheric polar vortex, implying insufficient stratospheric wave drag. In this study ...
On the Relationship between Incremental Analysis Updating and Incremental Digital Filtering
Publisher: American Meteorological Society
Abstract: Incremental analysis updating (IAU) refers to a method of smoothly inserting instantaneous analysis increments into a numerical model by spreading the increments over a time period. In this work, this method is shown to ...
The Canadian Seasonal to Interannual Prediction System. Part I: Models and Initialization
Publisher: American Meteorological Society
Abstract: he Canadian Seasonal to Interannual Prediction System (CanSIPS) became operational at Environment Canada's Canadian Meteorological Centre (CMC) in December 2011, replacing CMC's previous two-tier system. CanSIPS is a ...
The Stratospheric Extension of the Canadian Global Deterministic Medium-Range Weather Forecasting System and Its Impact on Tropospheric Forecasts
Publisher: American Meteorological Society
Abstract: new system that resolves the stratosphere was implemented for operational medium-range weather forecasts at the Canadian Meteorological Centre. The model lid was raised from 10 to 0.1 hPa, parameterization schemes for ...
Collaboration of the Weather and Climate Communities to Advance Subseasonal-to-Seasonal Prediction
Publisher: American Meteorological Society
Abstract: Weather Research Programme (WWRP) and the World Climate Research Programme (WCRP) have identified collaborations and scientific priorities to accelerate advances in analysis and prediction at subseasonal-to-seasonal time ...