1 A dual-polarization radar hydrometeor classification algorithm for ...

More documents

Recommendations

Info

148149150151152153154155156157158159160161162163164165166167Wet or melting snow was not modeled in this study but its inclusion in the classificationalgorithm is discussed in Section 4. A graupel category was not included because it was notobserved during any of our case studies, but can form in other winter storms around the world(Takahashi and Fukuta1988, Takahashi et al. 1999, Reinking 1975). Bullet, rosette, and stellarcrystal shape extensions are too complex to be resolved by K- through S- band frequency radars(Vivekanandan et al. 1994).i. Dendrites and platesBecause of their skeletal framework, dendrites are modeled with low ! bulk between 0.3-0.5 g cm -3 (Heymsfield 1972, Fukuta and Takahashi 1999). These branched crystals tend toflutter as they slowly fall with their maximum dimension oriented horizontally (PK97). This isrepresented with $ = 15° (Matrosov et al. 1996, KR11). We modeled PSDs observed by Lo andPassarelli (1982) for pristine dendrites prior to the onset of aggregation. Many studies haveconfirmed that an exponential PSD is sufficient to describe crystal populations (PK97).Dendrites can be longer (1.3 cm ‡ ; Mitchell et al. 1996, PK97, KR11) than plates, whichhave less favorable geometry for growth and are associated with lower ice supersaturations(usually unsaturated with respect to water; PK97, Foster and Hallett 2008). Plates are assumed tobe solid ice (PK97) and exhibit approximately the same canting behavior as dendrites. However,plates have more sloped PSDs because of their muted growth (Bader et al. 1987, Ryan 2000).Observed D and D 0 ranges from samples of unrimed plate populations (PK97) match thosemodeled for plates.‡ This scattering model could only simulate D MAX % 1 cm. PSD parameterizations were stilldeemed sufficient because D 0 was always well contained within D MAX (see Table 1) andsimulated D 0 ranges agree with D 0 observations for both snow types (see references in text).8
168169170171172173174175176177178179180181182183184185186187188189190The vertical thickness of plates and dendrites is the same but their horizontal dimensionsdiffer based on growth conditions and therefore dendrites are slightly more oblate (Auer andVeal 1970). We qualitatively followed the data from Auer and Veal (1970), but our modelbecomes computationally unstable for the very small a/b they suggest (
Page 1 and 2: 1234A dual-polarization radar hydro
Page 3 and 4: 35363738394041424344454647484950515
Page 5 and 6: 80818283848586878889909192939495969
Page 7: 12612712812913013113213313413513613
Page 11 and 12: 21421521621721821922022122222322422
Page 13 and 14: 26026126226326426526626726826927027
Page 15 and 16: 30630730830931031131231331431531631
Page 17 and 18: 35235335435535635735835936036136236
Page 19 and 20: 39839940040140240340440540640740840
Page 21 and 22: 44344444544644744844945045145245345
Page 23 and 24: 48949049149249349449549649749849950
Page 25 and 26: 53553653753853954054154254354454554
Page 27 and 28: 581582583584585586future. The desce
Page 29 and 30: 59960060160260360460560660760860961
Page 31 and 32: 64364464564664764864965065165265365
Page 33 and 34: 71071171271371471571671771871972072
Page 35 and 36: 77777877978078178278378478578678778
Page 37 and 38: 84384484584684784884985085185285385
Page 39 and 40: 878879880881Tables.Table 1: Microph
Page 41 and 42: 890891892893894Table 3: References
Page 43 and 44: 901902903904905906907Table 5: Slope
Page 45 and 46: 94594694794894995095195295395495595
Page 47 and 48: 963964965966967968Fig. 2: K dp, Z d
Page 49 and 50: 974975976977Fig. 4: C-band OU-PRIME
Page 51 and 52: 984985986987Fig. 6: X-, C-, and S-b
Page 53 and 54: 991992993Fig. 8: X-, C-, and S-band
Page 55 and 56: 99799899910001001Fig. 10: X-band CA
Page 57 and 58: 100610071008Fig. 12: S-band KICT Z
Page 59:
1013101410151016Fig. 14: X-band CSU
show all

1 A dual-polarization radar hydrometeor classification algorithm for ...

Create successful ePaper yourself

Delete template?

Save as template?