Lawrence Takacs

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A detailed description of the numerical formulation of Version 2 of the ARIES/GEOS "dynamical core" is presented. This code is a nearly "plug-compatible" dynamics for use in atmospheric general circulation models (GCMs). It is a finite difference model on a staggered latittMe-longitttde C-grid. It uses second-order differences for all terms except the(More)
The age of air has recently emerged as a diagnostic of atmospheric transport unaffected by chemical param-eterizations, and the features in the age distributions computed in models have been interpreted in terms of the models' large-scale circulation field. This study shows, however, that in addition to the simulated large-scale circulation,(More)
This presentation discusses the NASA data assimilation project at the Data Assimilation Office at the NASA/Goddard Space Flight Center. The goal is to produce accurate gridded datasets of atmospheric fields by assimilating a range of observations along with physically consistent model forecasts. This work produces datasets that are used by the climate(More)
We introduce the parallel grid manipulations needed in the Earth Science applications currently being implemented at the Data Assimilation OOce (DAO) of the National Aeronautics and Space Administration (NASA). Due to real-time constraints the DAO software must run eeciently on parallel computers. Numerous grids, structured and unstructured are employed in(More)
This presentation discusses the NASA data assimilation project at the Data Assimilation OOce at the NASA/Goddard Space Flight Center. The goal is to produce accurate gridded datasets of atmospheric elds by assimilating a range of observations along with physically consistent model forecasts. This work produces datasets that are used by the climate research(More)
This ooce note discusses the design of PILGRIM, a library which will support the manipulations of grids in Earth Science software currently being designed and implemented at the Data Assimilation OOce (DAO). It allows various grids to be distributed over an array of processing elements (PEs) and manipulated with high parallel eeciency. Unlike many parallel(More)
This document contains the requirements and design of the parallel God-dard Earth Observing System General Circulation Model (GEOS-3 GCM). This derives from a week-long internal workshop that were conducted at the NASA/Goddard Space Flight Center Data Assimilation OOce (DAO) from January 13 to 17 1997, and subsequent discussions within the DAO Modeling(More)