Size distribution of radar echoes from convective clouds around Delhi during monsoon season

摘要

The size distributions of radar echoes from convective clouds observed in Delhi region during each monsoon season of the 6-year period from 1967 to 1972 have been investigated. It has been found that the size distribution of about 99 per cent of the total echoes in each monsoon season and covering echoes up to diameter 35 km (30 km in 1972) are well represented by the exponential distribution N_D = a exp (- bD), where N_D is the number of echoes in the diameter interval D to D + ΔD, D is the mid-value of the interval, i.e. D + ΔD/2, and a and b are the coefficients to describe the exponential distribution. The possibility of using these results in connection with the estimation of rain attenuation for millimetre wave propagation has been discussed.