Diagram of the layers within Earth's atmosphere. Troposphere. The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense.Almost all weather is in this region. Stratosphere. The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high.he troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.
conus. n, pl-ni. 1. (Anatomy) anatomy zoology any of several cone-shaped structures, such as the conus medullaris, the lower end of the spinal cord. 2. (Zoology) anatomy zoology any of several cone-shaped structures, such as the conus medullaris, the lower end of the spinal cord. continental United States.
1. a large convex molding, semicircular in profile, commonly forming the lowest member of the base of a column, directly above the plinth. 2. a. a doughnut-shaped surface generated by the revolution of a conic, esp. a circle, about an exterior line lying in its plane. b. the solid enclosed by such a surface. 3. Bot. the receptacle of a flower. 4. Anat. a rounded ridge; a protuberant part.