NG32A-02
Connecting small-scale turbulence to large-scale dynamics in the mesosphere using the Mesosphere-Lower Thermosphere Turbulence Experiment (MTeX)
Wednesday, 16 December 2015: 10:32
300 (Moscone South)
Colin Charles Triplett1, Richard L Collins1, Gerald A Lehmacher2, Aroh Barjatya3, David C Fritts4, Franz-Josef Luebken5, Brentha Thurairajah6 and V Lynn Harvey7, (1)University of Alaska Fairbanks, Fairbanks, AK, United States, (2)Clemson University, Clemson, SC, United States, (3)Embry-Riddle Aeronautical University, Physical Sciences Department, Daytona Beach, FL, United States, (4)GATS, Inc., Newport News, VA, United States, (5)Leibniz Institute of Atmospheric Physics, Kühlungsborn, Germany, (6)Virginia Polytechnic Institute and State University, Blacksburg, VA, United States, (7)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States
Abstract:
The general circulation of the middle and upper atmosphere is determined by waves that form in the lower atmosphere. Large-scale Rossby waves and small-scale gravity waves propagate upward and release their energy in regions of instability such as critical layers. Rossby wave breaking leads to large scale disturbances in the wind and temperature fields known as a sudden stratospheric warming (SSW). These have a great impact on the seasonal weather and climate of the middle atmosphere. SSW events have a particular relationship with gravity waves in the Arctic middle atmosphere. During these events gravity waves reestablish geostrophic balance in the wind field, i.e. the stratospheric polar jet. This return to geostrophic balance, called geostrophic adjustment, generates gravity waves. We used the data from a recent rocket mission, lidar measurements, satellites, and MERRA to understand the coupling of small scale turbulent motions to large scale wave motions in the atmosphere. The Mesosphere-Lower Thermosphere Turbulence Experiment (MTeX) rocket investigation was composed of two rockets launched from Poker Flat Research Range on 25-26 January 2015. MTeX was launched into a mesospheric inversion layer (MIL) giving us a known meteorology. A neutral density sensor that measured turbulence at 20 cm scales flew on both MTeX payloads. Rayleigh lidar measurements of the stratosphere and mesosphere give us the temperature and density structure at kilometer scales characterized the mean environment as well as gravity waves and the MIL. Satellite measurements allow us to characterize the planetary wave activity. MERRA reanalysis gives us a characterization of the winds and planetary waves and their effect on the generation and propagation of waves from scales of tens to thousands of km. The combination of these three data sources and MERRA reanalysis gives us a view of the waves from the synoptic-scale generation and propagation of waves to the small-scale generation of turbulence. We can thus characterize the motions from waves to turbulence around a defined and persistent meteorological event to better understand turbulent transport in the mesosphere.
