TTUKa Radar Update

Several hours of coordinated data were collected this on the morning of 25 March 2015. TTUKa radar teams were deployed and scanning before 13 UTC to take full advantage of the precipitation. The precip began as rain and remained liquid for the first 45 minutes or so of data collection. During this time period, the radars were preforming virtual towers over the lidar supersite. The higher reflectivity allowed this with few clutter / side lobe issues. Precipitation quick transition to moderate snow around 14:20 UTC.  Wind speeds approaching 20 m /s were noted near the top of the RHI as well as in the BAO tower data. It will be interesting to note differences in dual-Doppler and lidar / tower wind speeds associated with different scatterers.

The homogenous nature of the reflectivity during the precip also allowed for collection of dual-Doppler sectors over the BAO site. In addition to the horizontal variability of the wind field, this scanning strategy will should also allow for the computation of vertical velocity. Sectors were preformed from 15:19 UTC through 16:27 UTC. Near the beginning of this segment, streaks were noted in the low level wind field. The "streaky" nature to the wind field gradual diminished through the collection of the dual-Doppler volumes. As seen from the perspective of TTUKa2:

We collected data until the precipitation ended, adding 383 minutes to being the total to 4987 minutes out of the available 7200.

Data from previous deployments continue to be minimally processed. The 23 March 2015 clear air data display many interesting features, including gusts and lulls: 

In the above animation, the radial velocity (m/s) from TTUKa2 is shaded. the dual-Doppler wind speed and direction profiles from the intersection point (vertical black line) are inset at the top left and right respectively. The mean wind speed and direction profiles for the entire time period (about 20 minutes) are also included as the dashed (dotted) gray profiles in the wind speed (direction) inset.

While clear air data quality were excellent for a while, we experienced an abrupt drop in coherent velocity data. This decrease is thought to be related to some virga-induced outflow that may have scoured the atmosphere:

We will continue to peruse the recently collected data for interesting features.