Introduction to Atmospheric Sciences comprises the physical, chemical and dynamical processes of the troposphere. The governing conservation (balance) equations for trace constituents, dry air,water substances, total mass (equation of continuity), energy (1st law of thermodynamics), entropy (2nd law of thermodynamics), and momentum (Newton’s 2nd axiom) are presented and explained. This presentation includes basics of cloud physics, and simplifications like the hydrostatic and geostrophic approximations and their application in models. Static and conditional stability criteria are explained too. Phenomena discussed include, for instance, frontal systems, hurricanes, föhn wind systems (Chinook), monsoon, El Nino Southern Oscillation (ENSO), ice fog. Chemical processes taking place in the atmosphere are analyzed based on kinetic processes, but thermodynamic equilibrium is also discussed. The discussion comprises, among other things, photolytic and gas phase oxidation processes, aqueous chemistry, as well as gas-to-particle conversion. Fundamentals of biogeochemical cycles (e.g. CO2, H2O, nitrogen, etc.) and the origin of the ozone layer are covered as well. The chapter on radiation includes solar and terrestrial radiation, major absorbers, radiation balance,radiative equilibrium,radiative-convective equilibrium, basics of molecular, aerosol, and cloud adsorption and scattering. Satellite imaginary, greenhouse gases (e.g., CO2, H2O, CH4, etc.), and optical phenomena like rainbows, halos etc. are included. Interactions of the global energy, water, and trace gas cycles and their influence on general circulation and their role in the climate system are presented. Moreover, fundamentals in numerical modeling of atmospheric and hydro-meteorological processes are provided.