Open AccessSnowfall rate estimation using C‐band polarimetric radars
Author(s) -
Hassan Diar,
Taylor Peter A.,
Isaac George A.
Publication year - 2017
Publication title -
meteorological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 59
eISSN - 1469-8080
pISSN - 1350-4827
DOI - 10.1002/met.1613
Subject(s) - nowcasting , snow , radar , remote sensing , meteorology , polarimetry , environmental science , precipitation , weather radar , algorithm , computer science , geology , geography , scattering , physics , telecommunications , optics
Radar quantitative precipitation estimation plays an important role in weather forecasting, nowcasting and hydrological models. This study evaluates the Sekhon and Srivastava (1970) snow water equivalent ( SWE ) algorithm currently implemented by the Canadian Radar Network of Environment and Climate Change Canada, suggests an improved algorithm and also evaluates the ability of polarimetric radars in estimating SWE . The radar data were collected from the dual polarimetric King City radar ( CWKR ) near Toronto, Ontario, and the Doppler Holyrood radar ( CWTP ) in Newfoundland. SWE data were collected at Oakville, Ontario, at Pearson International Airport ( CYYZ ), Toronto, Ontario, and at Mount Pearl, Newfoundland. The ground observations show that the polarimetric variables could be used to infer a few of the microphysical processes during snowfall. It is suggested that the co‐polar correlation co‐efficient ( ρ hv ) could be sensitive to the size ranges of different snow habits. Also, higher differential reflectivity ( Z dr ) values were measured with large aggregates. The results show a severe underestimation of SWE rates by the Sekhon and Srivastava algorithm. One hour accumulations from each site were used to develop SWE ( Z eH ) and SWE ( Z eH , Z DR ) algorithms ( Z eH and Z DR are the reflectivity factor and differential reflectivity, respectively). Similarly, algorithms were developed using SWE at 10 min intervals from CYYZ and Mount Pearl but these algorithms appeared to overestimate SWE . The hourly SWE accumulations from the three sites were combined to produce an additional SWE ( Z eH ) algorithm which showed better statistical results. A modest difference was found between the conventional and polarimetric algorithms for estimating snowfall amounts ( SWE ).