Middle atmosphere diagram

MSIS model temperatures for Davis in summer and winter.

MSIS model temperatures for Davis in summer and winter.

This diagram shows the temperature structure of the atmosphere up to 120 km above Davis station, Antarctica, in January and July. Temperatures are expressed in degrees Kelvin (K): 273 K equals zero degrees Celsius (C).

In summer (January), the temperature decreases in the troposphere from 275 K at the ground to 225 K at the tropopause (~10 km). The temperature rises in the stratosphere to reach ~280 K at the stratopause (~45 km). The atmosphere gets cooler with increasing altitude through the mesosphere reaching ~140 K at the mesopause. In the thermosphere the temperature rises rapidly to reach 400 K at an altitude of 120km.

In winter (July), the temperature decreases from ~265 K (-12°C) at ground level to ~185 K (coldest region in winter atmosphere) at ~30 km. In the stratosphere the temperature rises to 265 K at the stratopause (~55 km). The temperature then decreases to a value of ~205 K at the mesopause (~100 km). The temperature increases as we move up through the lower thermosphere and reaches 325 K by 120 km.

Atmospheric phenomena such as noctilucent clouds and aurora are also indicated at the approximate height at which they occur.

Diagram prepared by John French from MSIS empirical model data.