Tropospheric temperature refers to the temperature of the lowest layer of Earth's atmosphere, known as the troposphere. This layer extends from the ground up to an altitude of about 12 kilometers (7 miles) and is where most weather occurs. The term "tropospheric" comes from the Greek word for "turning," referring to the fact that temperature decreases with increasing height in this layer, causing air parcels to sink as they cool. Temperature measurements taken within the troposphere are important indicators of current and future weather conditions, as well as being used in climate research.