A term used to distinguish ozone present in the troposphere from the more commonly talked about stratospheric ozone layer. Tropospheric ozone results from transport from the stratosphere and from photochemical production (oxidation of carbon monoxide, methane, and other hydrocarbons). In remote regions of the troposphere, production and loss of ozone are nearly in balance, while in regions impacted by anthropogenic NO_x and hydrocarbon emissions, net ozone production occurs.