Atmospheric and Climate Sciences, 2022, 12, 475-492 https://www.scirp.org/journal/acs ISSN Online: 2160-0422 ISSN Print: 2160-0414 DOI: 10.4236/acs.2022.122028 Apr. 28, 2022 475 Atmospheric and Climate Sciences The Response of Geopotential Height Anomalies to El Niño and La Niña Conditions and Their Implications to Seasonal Rainfall Variability over the Horn of Africa Solomon Gunta 1 , Hejamady Gangadhara Bhat 2 , Busnur Rachotappa Manjunatha 2 1 Department of Physics, College of Natural and Computational Sciences, Wolaita Sodo University, Wolaita Sodo, Ethiopia 2 Remote Sensing and Geo-Informatics Division, Department of Marine Geology, Faculty of Science and Technology, Mangalore University, Karnataka, India Abstract In this study, we unveil atmospheric circulation anomalies associated with the large-scale tropical teleconnections using National Center for Environ- mental Prediction (NCEP) reanalysis dataset. Composite analyses have been performed to know the impact of large-scale tropical circulations on the Horn of Africa. The composite analysis performed at the geopotential height of 850 Mb and 200 Mb, and precipitation rate (mm/day) during six strong El Niño and La Niña episodes revealed that the large-scale tropical variability induced climate anomalies in space and time. A substantial decrease in upper-level height (200 Mb) has been observed in the study area during El Niño compo- site years as compared to the La Niña years. During El Niño conditions, the upper-level divergence initiates low-level vertical motion, thereby enhancing convection, however, during La Niña composite years, nearly contrasting sit- uations are noticed in Belg (February to May) season in Ethiopia. However, geopotential height anomalies at 850 Mb are above-normal during the strong El Niño years, suggesting suppressed convection due to vertical shrinking and enhancement of divergence at the lower level. Compared to the Belg (Febru- ary to May), geopotential anomalies were generally positive during the Ki- remt (June to September) season, thereby suppressing the rainfall, particular- ly in Southern Ethiopia and Northern Part of Kenya. In contrast, an increase in rainfall was observed during the Belg season (February to May). Keywords Geopotential Height, Composite Analysis, ENSO, Atmospheric Circulations, NCEP Reanalysis, Tropical SST Anomalies, Teleconnections, Belg, Kiremt How to cite this paper: Gunta, S., Bhat, H.G. and Manjunatha, B.R. (2022) The Response of Geopotential Height Anomalies to El Niño and La Niña Conditions and Their Implications to Seasonal Rainfall Variabili- ty over the Horn of Africa. Atmospheric and Climate Sciences, 12, 475-492. https://doi.org/10.4236/acs.2022.122028 Received: March 18, 2022 Accepted: April 25, 2022 Published: April 28, 2022 Copyright © 2022 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access