Global shifts in mountain wave turbulence within high resolution climate models

Abstract. Using a multi-model approach, this paper quantified global changes in moderate or greater mountain wave turbulence (MWT) within a high-end warming scenario. Initial results found model resolution dependency apparent, therefore three high resolution global climate modelled datasets were used within the analysis; HadGEM3-GC3.1-HM (25 km), EC-Earth-3P-HR (36 km) and MPI-ESM1.2-XR (34 km). Regional dependencies developed around each model and index, with seasonal components an important contributor to results. A sub-continental approach was developed, focusing on all regions in which MWT arose. On average, the North American continent projected an increase in MWT, but a decrease over the Rocky Mountain range. This decrease was apparent in all seasons but northern hemisphere (NH) winter, with an increase of +60.6 % over the 101 year investigation period. NH summer, spring and autumn dropped by -58.3 %, -41.2 % and -30.9 %. Over several mountain ranges an increase was evident, particularly over Greenland and regions in Asia. However, a drop in MWT also arose over the Alps, Atlas and northern and central Andes. Southern Andes and the Himalayas had seasonal differences resulting in a mix of projected outcomes. A final aim arose around the connection to low-level, surface wind flow and MWT production. This paper found links between MWT trends and the shift in projected median surface wind flow. The aviation sector should be aware of the future projections in MWT, particularly for those were large increase over the 101 year period were evident, such as Asia, Greenland and the Antarctic.