troposphere vs waft

troposphere

noun
  • The lower levels of the atmosphere extending from the surface of the Earth or another celestial body up to the tropopause. It is characterized by convective air movements and a large vertical temperature change. 

waft

verb
  • To be moved, or to pass, on a buoyant medium; to float. 

  • To give notice to by waving something; to wave the hand to; to beckon. 

  • To (cause to) float easily or gently through the air. 

noun
  • A flag used to indicate wind direction or, with a knot tied in the center, as a signal; a waif, a wheft. 

  • Something (such as an odor or perfume) that is carried through the air. 

  • A light breeze. 

How often have the words troposphere and waft occurred in a corpus of books? (source: Google Ngram Viewer )