Walter Fernández is President of the National Academy of Sciences of Costa Rica and Professor Emeritus of Atmospheric and Space Physics at the University of Costa Rica.

He graduated (B.Sc.) in Physics and Meteorology from the University of Costa Rica, obtained the M.Sc. degree in Meteorology from Saint Louis University, U.S.A., and got the Ph.D. degree in Physics from Imperial College London, University of London, United Kingdom. His main fields of research are the physical and chemical processes which occur in the atmospheres of Earth and other planets, with emphasis on the structure and dynamics of clouds and storms, applications of meteorological satellites, climatic variability and global change, and planetary atmospheres.

Professor Fernández was President of the Scientific Advisory Committee of the Inter American Institute for Global Change Research (IAI), President of the Commission of Geophysics of the Pan American Institute of Geography and History (PAIGH), President of the Board of Directors of the Latin American Center of Physics (CLAF), President of the Board of Directors of the National Research Council (CONICIT) of Costa Rica, and President of the Costa Rican College of Physicists (Colegio de Físicos).