327
Radar Polarimetry for Rain Estimation
The Bayesian retrieval gives a result that captures the temporal variation of rain
gauge measurement. The single-polarization estimator normally overestimates rainfall during the convection while performing fairly well in the stratiform region.
It is worth noting that mixtures of rain/hail might exist near the convective core
(e.g., around 0655 UTC at MINC), where radar-measured Z H and Z DR are sometimes
extremely large (e.g., Z H > 55 dBZ and Z DR > 3.5 dB). If quality control was not
30
20
10
0
30
20
10
0
30
20
10
0
30
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0
6:00
7:00
8:00
9:00
10:00
Time, UTC
Rain accumulation, mm
Rain gauge
Bayesian retrieval
R–Z H
(a)
(b)
(c)
(d)
(e)
(f )
11:00
12:00
6:00
0
5
10
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0
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FIGURE 13.9  One-hour rain accumulation comparison of radar retrievals and rain gauge
measurements at six sites: (a) CHIC; (b) MINC; (c) NINN; (d) SHAW; (e) SPEN; (f) WASH.
(From Cao, Q. et al., Journal of Applied Meteorology and Climatology, 49, 973, 2010. With
permission.)