Geoscience Reference
In-Depth Information
This corresponds to an ideal observing mode. The third scanning strategy appears to be
impossible to implement at a rate of one volume scan every 5-6 minutes using current
technology, but it may be possible using the high temporal resolution capabilities of next-
generation phased array radars (Heinselman & Torres, 2011).
Fig. 2. Radar beam heights for the three analysed scanning strategies. Radar beam paths
with elevation angles between 0.7° and 15.6° (17 PPIs) are shown as black lines, those with
elevation angles between 16.7° and 18.9° are shown as blue lines, and those with elevation
angles between 20.1° and 32° are shown as red lines.
4. Results
Figure 3 shows the mixing ratio of rain and the distribution of horizontal and vertical winds
at an altitude of 4 km ASL. The Weak Echo Region (WER) within the strong updraft region
was well simulated (the maximum updraft was 25 m s
-1
). These strong updrafts were fed by
southeasterly inflow below 1.5 km ASL (data not shown). Northwesterly wind was
dominant at 4 km ASL, and advected the area of heavy precipitation toward the southeast
(Fig. 3). Three downdraft cores were simulated at 4 km ASL. The first of these was located in
the heavy rain region to the east of updraft, and was associated with precipitation loading.
The second downdraft core was located in the light rain region to the southeast of the
updraft, and was related to the melting and sublimation cooling of ice-phase precipitation
(Shimizu et al., 2008). The third downdraft core was located in the non-precipitating region to
the south of the updraft, and was associated with compensation for the nearby strong updraft.
The strong updraft, first downdraft, and second downdraft cores were also simulated at 2 km
ASL (Fig. 4). The maximum updraft speed exceeded 18 m s
-1
at 2 km ASL. Anticlockwise wind
