Vertical structure of the lower troposphere derived from MU radar, unmanned aerial vehicle, and balloon measurements during ShUREX 2015

摘要: The ShUREX (Shigaraki UAV Radar Experiment) 2015 campaign carried out at the Shigaraki Middle and Upper atmosphere (MU) observatory (Japan) in June provided a unique opportunity to compare vertical profiles of atmospheric parameters estimated from unmanned aerial vehicle (UAV), balloon, radar data lower troposphere. present work is intended primarily as demonstration potential offered by combination these three instruments for studying small-scale structure dynamics Here, we focus on collected almost simultaneously two instrumented UAVs meteorological balloons, near MU operated continuously during campaign. flew along helical ascending descending paths nearly constant horizontal distance (~ 1.0 km), while balloons launched site drifted up ~ 3–5 km altitude range comparisons (~ 0.5 4.0 km) due wind advection. Vertical squared Brunt-Vaisala frequency N2 gradient generalized refractive index M2 were resolution 20 m pressure, temperature, humidity radiosondes. Profiles also echo power incidence sampling various time resolutions (1–4 min). shear S so that independent estimates Richardson number (Ri = N2/S2) could be obtained 150 m. Ri showed remarkable agreement all altitudes. We show detected same prominent temperature gradients, down decameter scales stratified conditions. These gradients extended horizontally over few kilometers least persisted hours without significant changes, indicating turbulent diffusion was weak. Large discrepancies between N2and M2 derived UAV, found layer generated Kelvin-Helmholtz (KH) flow instability height 1.80 2.15 km. cause appears depend stage KH billows.