The Basics of the Atmosphere

Solar energy powers the climate systemClimate system, but energy received at the Earth’s surface varies across space and time. Radiation laws quantify the amount of radiation emitted by wavelengthWavelength on the electromagnetic spectrumElectromagnetic spectrum. The position of the Earth, and any location on it, with respect to the Sun’s most direct emitted (shortwave) radiation, along with the extent to which the solar radiation is absorbed, scattered, or reflected before it reaches the surface, all affect the radiant energy intensity incident at a place. In turn, each location on Earth emits longwave radiation. The accounting for shortwave and longwave radiation inputs and outputs at a location—net radiation (Q*)—is the radiation balance. Excess radiant energy input is expended through the convective (turbulent) fluxes of latent and sensible heatSensible heat and the conductive substrate heat flux, which together comprise the energy balanceEnergy balance. Positive Q* increases temperature, which, along withand humidity humidity(L↓)and cloudand humidity, is a key component of local weather and climate. A stable atmosphereAtmosphere, including cases of a temperature inversion, is one in which a hypothetical air parcel will not rise spontaneously. In unstable atmospheresUnstable atmosphere, spontaneous rising motion can support vertical cloudand cloud types development, and, in the presence of abundant humidity, can cause clouds and precipitation.