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This paper describes a novel use of A-Train observations to estimate vertical velocities for actively growing convective plumes and to relate them to cloud internal vertical structure. Convective vertical velocity is derived from time-delayed (1–2 min) IR measurements from MODIS and IIR. Convective vertical velocities are found to be clustered around 2–4 m/s but the distributions are positively skewed with long tails extending to larger values. Land convection during the 13:30 overpasses has higher vertical velocities than those during the 1:30 overpasses; oceanic convection shows the opposite, albeit smaller, contrast. Our results also show that convection with larger vertical velocity tends to transport larger precipitation-size particle and/or greater amount of water substance to higher altitude and produces heavier rainfall. Finally, we discuss the implications of this study for the designs of future space-borne missions that focus on fast-evolving processes such as those related to clouds and precipitation.

[1] Satellite imagery and C-band radar on the R/V Mirai detected an isolated convective cloud band over the western tropical Pacific, and dropsondes observed the surrounding atmospheric environment. The reasonable development mechanism of this unusual cloud band is investigated using observational and numerical simulation data. Although theoretically, the surrounding atmospheric profile supported convective rolls, only a single cloud band was developed. Numerical simulations revealed a single cloud band and roll structure without condensate in the boundary layer. A westerly jet just above the cloud band influenced the environment with strong vertical shear supporting convective rolls; this was maintained by a typhoon at a distance of 1500 km away. A large-scale convergence in the meridional wind was also accompanied with this westerly jet. This special environment made by a typhoon could develop the unusual single cloud band.

[1] We performed synergy observation of subvisual cirrus clouds (SVC) with 1064-nm lidar, 95-GHz cloud radar and radiosondes launched every 3 hours at 2°N, 138°E for one month from 9 November to 9 December 2001. The estimated effective radius reff of SVC is 9–16 μm (5–9 μm in mode radius). This assumes that the shape of cloud particles is spherical and the number concentration of the particles is 105 m−3. SVC disappear when temperature anomalies exceed +1.5°C. The fall velocity of SVC is same as the downward velocity of the phase propagation of the Kelvin wave, and the terminal velocity of hexagonal particles. Thus sedimentation and phase propagation are important for dissipation of SVC. In addition, it was noted that SVC tended to disappear at midday during the observational period except on 27 November 2001.