Coordinated investigation of midlatitude upper mesospheric temperature inversion layers and the associated gravity wave forcing by Na lidar and Advanced Mesospheric Temperature Mapper in Logan, Utah

摘要: Mesospheric inversion layers (MIL) are well studied in the literature but their relationship to dynamic feature associated with breaking of atmospheric waves mesosphere/lower thermosphere (MLT) region not understood. Two strong MIL events (ΔT ~30 K) were observed above 90 km during a 6 day full diurnal cycle Na lidar campaign conducted from August 13 Logan, Utah (42°N, 112°W). Colocated Advanced Temperature Mapper observations provided key information on concurrent gravity wave (GW) and characteristics nighttime observations. The study found both MILs correlated development presence an unstable ~2 km peak altitudes highly stable below, implicating strengthening is likely due increase downward heat flux by enhanced saturation wave, when it propagates through layer. Each event also exhibited distinct features: one showed progression most tidal-GW interaction, while height other remained constant. During further investigation stability surrounding structure, measurements indicate sharp enhancement convective below altitude each MIL. We postulate that sources these different; was potentially triggered large tidal activity passage mesospheric bore.