Atc. Chang et al., RANDOM ERRORS OF OCEANIC MONTHLY RAINFALL DERIVED FROM SSM-I USING PROBABILITY-DISTRIBUTION FUNCTIONS, Monthly weather review, 121(8), 1993, pp. 2351-2354
Global averages and random errors associated with the monthly oceanic
rain rates derived from the Special Sensor Microwave/Imager (SSM/I) da
ta using the technique developed by Wilheit et al. are computed. Accou
nting for the beam-filling bias, a global annual average rain rate of
1.26 m is computed. The error estimation scheme is based on the existe
nce of independent (morning and afternoon) estimates of the monthly me
an. Calculations show overall random errors of about 50%-60% for each
5-degrees X 5-degrees box. The results are insensitive to different sa
mpling strategy (odd and even days of the month). Comparison of the SS
M/I estimates with raingage data collected at the Pacific atoll statio
ns showed a low bias of about 8%, a correlation of 0.7. and an rms dif
ference of 55%.