This document provides an introduction to the course Meteorology PHYSCI 102A. It defines meteorology as the study of the atmosphere, atmospheric phenomena, and atmospheric effects on weather. The main focus is on the lower atmosphere where most weather occurs. Meteorology is a subdiscipline of the broader atmospheric sciences. The document outlines several branches of meteorology including climatology, topclimatology, barometry, paleoclimatology, paleotempestology, atmospheric physics, aeronomy, radiometry, hydrometeorology, geomagnetism, geophysics, bioclimatology, geobiology, and biometeorology. These branches cover various topics like the study of weather, climate, atmospheric pressure