Ian Folkins

TL;DR: The Tropical Tropopause Layer (TTL) as discussed by the authors is a 3D model of the troposphere, and it has been shown that the transition from troposphere to stratosphere occurs in a layer, rather than at a sharp "tropopause".

TL;DR: In this article, a three-dimensional chemistry-transport model of the stratosphere is used to simulate the evolution of trace constituents during the 1991-1992 Arctic winter, and it is shown that heterogeneous reactions on polar stratospheric clouds led in early January to almost complete activation of atmospheric chlorine inside the polar vortex, in remarkable coincidence with observations by the ER-2 aircraft and the microwave limb sounder on the Upper Atmosphere Research Satellite.

TL;DR: In this paper, the authors used ozonesondes launched from Samoa (14°S) during the Pacific Exploratory Mission (PEM) Tropics A to show that O3 mixing ratios usually start increasing toward stratospheric values near 14 km.

TL;DR: In this paper, a global chemical transport model (GEOS-Chem) is used to identify locations and time periods in which lightning would be expected to dominate the trace gas observations.

TL;DR: The ozone profile in the tropics is shaped like an S, with a minimum at the surface, a maximum at 330 K (∼6.5 km), another minimum at 345 K ( ∼11.2 km), and a subsequent increase toward the tropopause.