TITLE:
Consistency in Z-R Relationship Variability Regardless Precipitating Systems, Climatic Zones Observed from Two Types of Disdrometer
AUTHORS:
Bakary Bamba, Abé Delfin Ochou, Eric-Pascal Zahiri, Modeste Kacou
KEYWORDS:
Drop Size Distributions, Consistency in Z-R Relationship Variability, Squall Lines, Thunderstorm, Stratiform Rain, JW RD-69 Disdrometer, Optical Spectro-Pluviometer OSP
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.4 No.5,
December
23,
2014
ABSTRACT: Data from rain Drop Size Distributions gathered on five sites in Africa
as well as those of the pilot site in Kourou (French Guyana, South America),
located in different climatic zones, and collected by two types of disdrometer
(the impact JW RD-69 disdrometer and the Optical Spectro-Pluviometer, OSP) are
used to study the consistency of the reflectivity factor-rain rate at the
ground (Z-R) relationship
variability. The results clearly confirm that the relationship Z-R knows a large spatial variability, from a type of precipitation to
another and within the same precipitation regardless the type of
disdrometer used for DSD measurements. Base on the similarity of the relations
reflectivity factor-rain rate and ratio median volume diameter over the total
number of drops-rain rate, the variability of the Z-R coefficients (A, b) through the simultaneously
implication of the size and number of drops which characterize the DSD was
exhibited. It was shown that the relationships A-α and b-β designed to
understand the involvement of parameters D0 and NT of DSD in the
variability of the relationship Z-R are similar regardless the types of disdrometer used. However, the relations A-α in the Sahelian region appear to
deviate from those of Guinean, equatorial and Soudanian zones. The plausible
reasons were discussed.