THE HAIL CHARACTERISTICS INFLUENCE ON ITS ACCRETIONAL GROWTH

A new method for partitioning of graupel and hail in modeled hail accr etion rates as used in bulk parameterization schemes is derived. The i nfluence of the diameter size limit between graupel and hail populatio ns on new rates is also considered. The new hail accretion rate for th e hail/rain case is over thirty-seven times higher than its former val ue with hail alone if the total hail mixing ratio is greater than 10(- 3) kg kg(-1). This increase is over ten times for the hail/snow case, while the new rate of hail accreting cloud water (ice) differs little from its former value. The truncating effects (effect of the diameter size limit between graupel and hail) are also important, especially in the hail/snow case (new accretion rate is 23 times lower compared to its former value). Such difference is due entirely to the large lower end of the hail spectrum. (C) 1997 Elsevier Science B.V.