High Latitude Mesospheric Dynamic and Chemistry Studies

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This study has two objectives:1) a primary objective, to measure and study the Acoustic Gravity Wave (AGW) structure and flux into the mesosphere at Sonderstrom, Greenland, a high latitude station. The studies of structure in airglow imagery can now be used to calculate the vertical flux of horizontal momentum carried by the AGWs with large vertical wavelengths. Airglow imagers are uniquely capable of measuring the AGWs with large phase speeds (short periods) that carry the major portion of the wave momentum flux in the mesosphere. Specifically, comparisons will be made to similar measurements being made at Albuquerque, N.M., a low-mid latitude station, and South Pole station.2) A secondary objective, to make measurements of, and study, mesospheric emissions related to sporadic metal layers in the mesosphere. Recent studies suggest these may involve high latitude layers and, there may be chemical heating associated with some releases.For extracting intrinsic wave measurements, it is important to make Doppler corrections for winds. A meteor radar is now active at Sonderstrom which is able to make this measurement. Rayleigh lidar routinely make scattering measurements of structure in the stratosphere and lower mesosphere and Na lidar in the upper mesosphere. The lidars observe slower speed AGWs that complement the spectrum observed by the airglow. This data will be assimilated and used to 1) quantify the vertical flux of horizontal momentum and energy carried by the waves at Sondrestrom, and 2) compared with data being gathered at a low latitude site, Albuquerque.Atmospheric dynamic and chemical processes at high latitude are unique, especially the thin and sporadic layer phenomena. It is important to resolve the chemical processes during these events through the measurements of airglow chemiluminescent emissions. Routine measurements of airglows will be accomplished by spectral discrimination of key emissions with a continuous night time operation of a spectrometer and photometers.