In the tropical stratosphere, deep layers of eastward and westward winds encircle the globe
and descend regularly from the upper stratosphere to the tropical tropopause. With a …

As the most dominant variability of the tropical stratospheric zonal winds on the interannual
timescale, the quasi-biennial oscillation (QBO) has a significant impact on weather and …

Abstract The Quasi‐biennial Oscillation (QBO) dominates the interannual variability of the
tropical stratosphere and influences other regions of the atmosphere. The high predictability …

We introduce a new climate model (GISS E2. 2) that has been specially optimized for the
middle atmosphere and whose output is being contributed to the CMIP6 archive. The top of …

Gravity waves play a significant role in driving the semiannual oscillation (SAO) of the zonal
wind in the tropics. However, detailed knowledge of this forcing is missing, and direct …

The representation of the semi‐annual oscillation (SAO) in climate models shows a common
easterly bias of several tens of metres per second compared to observations. These biases …

Extreme polar vortex events known as sudden stratospheric warmings can influence surface
winter weather conditions, but their timing is difficult to predict. Here, we examine factors that …

The simulated stratospheric dynamics have been improved compared to previous
generations in many climate models taking part in the Coupled Model Intercomparison …

The semiannual oscillation (SAO) in zonally averaged zonal winds develops just above the
quasi-biennial oscillation (QBO) and dominates the seasonal variability in the tropical upper …

The influence of the Semi‐Annual Oscillation (SAO) on the timing and evolution of major
sudden stratospheric warmings (SSWs) is examined using the 2008/2009 SSW as the …