The lowest part of the troposphere, where friction with the Earth's surface influences air flow, is the planetary boundary layer. This layer is typically a few hundred meters to 2 km (1.2 mi) deep depending on the landform and time of day.he troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere 's mass and 99% of its water vapor and aerosols.
Bushnell is a city in Sumter County, Florida, United States. The population was 2,050 at the 2000 census. According to the U.S Census estimates of 2005, the city had a population of 2,119. It is the county seat of Sumter County.
St. Lucie County, Florida (FL) County population in 2014: 291,028 (97% urban, 3% rural); it was 192,695 in 2000. County owner-occupied with a mortgage or a loan houses and condos in 2010: 53,447. County owner-occupied free and clear houses and condos in 2010: 27,319.