Diabatic Divergence Profiles in Western Pacific Mesoscale Convective Systems

摘要: Abstract Heating in the atmosphere can be expressed as diabatic divergence δd, which is nearly equal to actual horizontal δ tropical convection. High-quality profile measurements from airborne Doppler radar “purls” ten mesoscale convective systems (MCS) observed during TOGA-COARE are examined, and mean compared with rawinsonde array measurements. Young features have strong near-surface convergence, while older cells better-developed downdrafts stratiform precipitation areas their peak convergence aloft. In mean, then, surface flow only weakly convergent or oven divergent, so that main into MCSs deep peaked aloft, a sharp “melting convergence” at 0°C. Divergence prevails above ∼10 km altitude but was undersampled by radar. Unusual well-sampled observations purl dataset include: persistent, widespread feature one MCS (a cyclone rainband); oscillatory “reverberations” c...