Statistical Study of Cloud Vertical Structure in Troposphere Derived from High Resolution
Radiosonde Measurements Over Addis Ababa - Ethiopia (9.010 N, 38.760E)
Asmarech Eshet and U Jaya Prakash Raju
Department of Physics, College of Science, Bahir Dar University, Bahir Dar, Ethiopia
*Corresponding Author: U Jaya Prakash Raju, Department of Physics, College of Science, Bahir Dar University, Bahir Dar, Ethiopia.
November 23, 2022; Published: December 14, 2022
Clouds are mixtures of water droplets or ice crystals suspended at a certain height in the atmosphere, and formed when water vapor in the atmosphere reaches saturation. They are significant in the global radiation budget, atmospheric circulation, and hydrological cycle. However, knowledge regarding the observed climatology of the cloud vertical structure (CVS) over Ethiopia is still poor. Based on four years high-resolution radiosonde observations in Addis Ababa, Ethiopia (9.010 N, 38.760E), the CVS climatology, including the frequency distribution and seasonal variations, are investigated. Overall, the occurrence frequency of clear sky cases in Addis Ababa is slightly higher than that of cloudy sky cases, and cloud occurrence of frequency is highest in kiremt and lowest in bega. This is related to the accumulation of moisture in the atmosphere due to the effect of Inter Tropical Convergence Zone in the summer (kiremt) season. The occurrence of midlevel cloud is more frequent than that of high level cloud in all years demonstrating that mid-level cloud is dominant over Addis Ababa. The average cloud top height (CTH), cloud base height (CBH), and cloud thickness for mid-level clouds are 5 km, 2.4 km, and 2.6 km respectively. In case of high level clouds, CBH is 5.2 km having a CTH of 9.8 km, with cloud thickness of 4.6 km.
Keywords: Radiosonde; Cloud Vertical Structure; Relative Humidity; Dew Point Depression
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