Dynamical effects of atmospheric gravity waves in the upper troposphere and stratosphere as revealed by a high-resolution reanalysis.

Gravity waves (GWs) are ubiquitous in stably stratified background states of the atmosphere from the boundary layer to the thermosphere. As a mesoscale phenomenon with typical scales smaller than the model effective resolution, they need to be parameterized in climate models based on numerous underlying simplifications. However, our understanding of the GW climate impacts is based mainly on their parameterized effects and may be model dependent and with uncertain relation to the real atmosphere dynamics.

                  Based on the whole span of the ERA5 reanalysis, here I present a "quasi - observational" assessment of GW dynamical effects in the extratropical upper troposphere and stratosphere. Part of our results confirms the textbook knowledge and expectations regarding the gravity wave role in decelerating the jet streams. But, after a closer inspection of the data, we found also previously unreported interactions and dynamical effects connected with GWs in the vicinity of the subtropical jet that can change the way how we parameterize them.