The estimation of convective rainfall by area integrals 2. The height-area rainfall threshold (HART) method

Estimates of instantaneous area average rain rate ( in millimeters per hour) are obtained with 5-10% accuracy over a large domain simply by measuring 1) the fraction of the area, F(τ) covered by rain intensity greater than a selected threshold τ and 2) the average precipitating cloud top heights. The results from all locations were found to be consistent and physically plausible. The cloud base temperature seems to play a major role in the deterrmination of the constants of the HART method. The -F(τ) relations were found to be rather insensitive to variations in the Z-R relationships. However, any bias in the measurement of τ causes a similar bias in the derived . HART makes possible the accurate estimation of instantaneous rainfall from space when measuring the area and height of the convective rain systems with radar. -from Authors