Impact of the stratospheric quasi-biennial oscillation on tropospheric weather phenomena

Fri., Jan. 15, 2021 3:30 p.m. - Fri., Jan. 15, 2021 4:30 p.m.

Location: Zoom

Abstract: Temperatures in the tropical stratosphere, the atmospheric region between 20°S-20°N and above 18 km, oscillate between colder and warmer conditions with a full cycle taking about 28 months on average. Observations over the last decades have shown that the strength of this so-called quasi-biennial oscillation of stratospheric temperature is similar for all longitudes within the tropics. The temperature variations extend downward into the region that connects the stratosphere with troposphere. This presentation shows that in this transition region between the two atmospheric layers, the temperature oscillations can be stronger or weaker depending on the geographical position along the equator. Especially strong temperature oscillations are found over regions of frequently occurring thunderstorms such as the West Pacific and Africa. The fact that a stratospheric signal such as the quasi-biennial oscillation is linked with thunderstorms has implications for understanding how the upper atmosphere can impact tropical weather phenomena.

Speaker: Dr. Susann Tegtmeier, University of Saskatchewan

*Part of the 2021 Prairie University Physics Seminar Series (PUPSS)