INTERNAL GRAVITY WAVES ACTIVITY HOTSPOT AND IMPLICATIONS FOR THE MIDDLE ATMOSPHERIC DYNAMICS

摘要

Internal gravity waves are widely recognized torncontribute significantly to the energy and angularrnmomentum transport. They play a significant role inrnaffecting many of the middle atmospheric phenomenarn(like the QBO or Brewer-Dobson circulation). UsingrnGPS RO density profiles, we have discovered arnlocalized area of enhanced IGW activity and breaking inrnthe lower stratosphere of Eastern Asia/North-westernrnPacific region.rnWith a 3D primitive equation model of the middlernatmosphere we studied the effects of such a localizedrnbreaking region on large-scale dynamics and transport.rnPossible forcing and propagation directions of planetaryrnwaves caused by such a localized IGW forcing wererninvestigated and consequences for the polar vortexrnstability and stratosphere-troposphere exchange in therntropical region were discussed.rnFinally, applying 3D EP flux and 3D residualrncirculation diagnostics, we investigated the possible rolernof this area in the longitudinal variability of the Brewer-rnDobson circulation with a hypothesis of its enhancedrndownwelling branch in this region. In the proces, modelrnresults were compared with the ozone and tracerrndistribution data from GOME, GOMOS, MIPAS andrnSCIAMACHY further confirming the importance ofrnthe Eastern Asia/North-western Pacific region forrnmiddle atmospheric dynamics.