Technology

Real-Time Four Dimensional Data Assimilation (RTFDDA)

The Real-Time Four Dimensional Data Assimilation (RTFDDA) system is a computer-model that was originally developed by NCAR for producing analyses of current meteorological conditions and forecasts for U.S Army test ranges. Since then, the system has been adopted by other DoD and government agencies for support of special missions and for homeland-security applications.

RTFDDA focuses its computational resources on forecasting for specific geographic areas - not the entire continent, for example. This narrow focus enables the model to resolve a greater number of meteorological features while maintaining accuracy. The forecasting system can be deployed worldwide to address threats of a human or man-made nature. For example, RTFDDA has been used for counter-terrorism support for both the Athens and Salt Lake City Olympics and to forecast the movement of hazardous material potentially released into the atmosphere. The system was used by the Army to support operations in Afghanistan and Iraq and it provided superior forecasts of Hurricane Rita in September 2005. In summary, the system excels at representing the details of the day-to-day weather in urban areas, as well as the extreme weather associated with hurricanes and thunderstorms.

Hardware

NCAR has partnered with three commercial providers of hardware systems for running the models and other 4DWX subsystems:

Aspen Systems: Linux Cluster Technology

Aspen has provided robust and cost-effective Linux clusters in lieu of using the more expensive shared memory platforms, which were originally used to implement 4DWX modeling systems.

Two 64-processor Linux clusters were employed, one was located at Dugway Proving Ground and the other was at NCAR. Two identical RTFDDA systems were running independently on each of the machine, which ensures a high reliability of the model products.