L. Mosimann, AN IMPROVED METHOD FOR DETERMINING THE DEGREE OF SNOW CRYSTAL RIMING BY VERTICAL DOPPLER RADAR, Atmospheric research, 37(4), 1995, pp. 305-323
An improved method is described to quantitatively determine the degree
of snow crystal riming in stratiform precipitation using vertically p
ointing Doppler radar. Using this method, an automatic determination o
f the degree of riming at any height above the melting layer is possib
le. The quantitative statement of snow crystal riming with a limited u
ncertainty is obtained by a strict separation of stratiform and convec
tive precipitation. For stratiform precipitation, the uncertainty of t
he degree of riming determined by this remote sensing technique typica
lly remains below one unit on a six step riming scale with somewhat la
rger uncertainties for very weak riming. A criterion is given for when
the situation is stratiform enough to use the proposed method for det
ermining the degree of snow crystal riming. This method is usefull in
all studies where direct crystal observation is not possible and the d
egree of riming is needed with good time resolution over a longer time
period and in different altitudes.