Physical Causes of Multi-scale temporal variability of DE3

Abstract:

It is well known in recent years that atmospheric tide DE3 originating in the lower atmosphere is an important driver of ionosphere E-region dynamo variability. However, the present understanding of its ionosphere/thermosphere (IT) impact is limited by our knowledge of its multi-scale temporal variability.

Full momentum and thermodynamic budgets of DE3 are calculated based on the nudged extended Canadian Middle Atmosphere Model (eCMAM) 30-year run (1979-2010). eCMAM30 extends from the Earth’s surface to ~220 km and is nudged toward ERA-Interim – the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis winds and temperature data –up to the pressure level of 1 hPa. The seperation of different terms in the momentum and thermodynamic budgets should give us a more detailed insight of the major sources of, and processes responsible for the multi-scale temporal variability of DE3, e.g. 1) inter-annual variation and its coupling with ENSO and QBO, 2) seasonal variation, and 3) short-term variation.