Cloud cover statistics and their diurnal variation have been obtained from in situ and satellite measurements for
three equatorial locations. Cloud liquid water content, 0 °C isotherm height and cloud attenuation have also been
obtained from radiosonde measurement using the so-called Salonen model at Kuala Lumpur (Malaysia). The
results show a strong seasonal variation of cloud cover and cloud liquid water content on the two monsoon
seasons. The Liquid Water Content (LWC) obtained from radiosonde and the Tropical Rainfall Measuring Mission
(TRMM) Microwave Imager (TMI) is higher during the Northeast Monsoon season, which corresponds to the
period of higher percentage cloud cover and high rainfall accumulation. The International Telecommunication
Union—Region (ITU-R) model underestimates the cumulative distribution of LWC values at the present station.
The relationship of the cloud attenuation, derived from the profiles of liquid water density and temperature within
the cloud, shows an underestimate by the data obtained from the ITU-R model. The cloud attenuation at Kuala
Lumpur is somewhat underestimated by the ITU-R model up to about 1.2 dB at Ka (30 GHz) and 3.4 dB at V (50
GHz) bands. The results of the specific attenuation can be used for the estimation of cloud attenuation at
microwave and millimetre wave over earth-space paths. The present data are important for planning and design of
satellite communications at Ka and V bands on the Earth–space path in the equatorial region
