Developed by ASR researchers at Brookhaven National Laboratory (BNL), the new BNL Doppler Radar Spectra Visualization and Analysis Java Toolkit is an application supporting all ARM Facility profiling radars that collect Doppler spectra. It is designed to facilitate the efficient interactive exploration, discovery, and physical characterization of novel radar Doppler spectrum features, aided through context provided by a range of additional non-radar measurements.
The toolkit simultaneously visualizes any user-defined combination of parameters from one or more radars, including power spectra, time/height spectrograms, and Micro-Active Remote Sensing of Clouds (MICROARSCL) extended moments (e.g., spectral skewness, kurtosis, etc.) in co-polarized and/or cross-polarized modes. Support is also provided to co-visualize five types of lidar data (Doppler, Raman, micropulse, high-spectral resolution, and ceilometer), balloon soundings, microwave radiometers, and irradiance sensors to exploit known and unknown synergies. As the user dynamically explores a quantity of interest, adjusting resolution at will, all other data displays remain synchronized in extent and positioning across all dimensions (time, height, and velocity) to elucidate relationships among all parameters.
Example case: Mixed-phase clouds in Barrow, Alaska
In the example shown, a complex mixed-phase case in Barrow, Alaska, is depicted by observations from four different instrument platforms. The micropulse lidar backscatter and depolarization in the upper left and middle panels indicate the presence of liquid layers at 1 and 2 kilometers. The visualizer crosshair has been positioned on the lower layer at 19.8 UTC and is replicated automatically in all other panels. The KAZR time spectrogram in the upper right panel reveals the same liquid layer as the lowest streak, with Doppler velocities undulating around values of 0 m/s.
The bottom left panel shows a clear quad-modal power spectrum, with the left-most local maximum corresponding to liquid. The other maxima indicate the presence of additional falling particle populations. The next bottom panel shows a range profile spectrogram, in which the liquid appears as the feature at the crosshair position. Finally, the last two panels indicate a liquid water path of 0.13 millimeters at 19.8 UTC and a temperature at the first liquid layer of about -14 degrees C.
Explore the Toolkit
A core design principle of the toolkit is a high degree of flexibility for the user to adapt to the specifics of a particular application. Future capabilities may include peer-to-peer synchronization to enable a team of collaborators at different locations to explore data together in real time. Not just for power users, the toolkit is also an ideal way for newcomers to radar Doppler spectra to come up to speed and requires little effort to install. The toolkit is available for download on the BNL website.
This work was supported by the U.S. Department of Energy’s Office of Science, through the Biological and Environmental Research program as part of the Atmospheric System Research program.