Technology

Real-Time Four Dimensional Data Assimilation (RTFDDA)

A high-resolution data assimilation system developed by RAL’s Yubao Liu. It runs with the Penn State/NCAR MM5 Mesoscale Model and provides regional weather forecasts. It also has an interior grid centered over the Washington metropolitan area that runs at very high resolution.

Variational Doppler Radar Assimilation System (VDRAS)

Developed by Jenny Sun and Andrew Crook (both MMM/RAL), it provides detailed and frequently updated information on wind, rain, and other real-time weather developments. VDRAS is the first real-time system to diagnose low-level wind and temperature over a wide region using four dimensional data assimilation of Doppler radar data.

Variational Lidar Assimilation System (VLAS)

A Doppler lidar variant of VDRAS. Also developed by Jenny and Andrew, this provides similar information as VDRAS, but at very high resolution, suitable for estimating winds at the neighborhood scale.

Computational Fluid Dynamics (CFD)

A building-scale, computational fluid dynamics model to track the winds and movement of particles and chemicals around the Pentagon. Although this system is being developed by another organization, NCAR is testing its own version, developed by MMM’s Piotr Smolarkiewicz.

Operational Algorithms

Multiscale model blending
Source term reconstruction
Locating sources
Sensor placement

Sensors

Standoff sensors (with subcats)
Point sensors (with subcats)