Index Geophysics

Tropical, oceanic, deep convective cloud morphology as observed by CloudSat

An investigation into the physical shape and size of mature, oceanic, tropical, deep convective clouds is conducted. A previously developed CloudSat data-partitioning methodology is used that separates components of cloud objects and measures their various length scales. In particular, the cloud objects are divided into a lower "pedestal" region on which the upper-level "anvil" region sits. Mean cloud objects are discussed in the framework of this morphological partitioning. For single-core clouds, the mean cloud has an anvil width of 95 km, a pedestal width of 11 km, and an anvil thickness of 6.4 km. The number of identified convective cores within the pedestal correlates positively with certain cloud length scales and morphological attributes of cloud objects such as anvil width. As the number of cores increases, the width of cloud objects is observed to grow. Pedestal width is shown to regress linearly to anvil width when a 2/3rd power scaling is applied to pedestal width. This result implies a decrease in the anvil width to pedestal width ratio with growing pedestals and an equivalence between the mass convected through the pedestal top and that into the anvil. Taller clouds are found to be wider. Some of the results obtained using the CloudSat methodology are also examined with a large-domain radiative-convective equilibrium numerical simulation and are found to exhibit similar trends when modeled. Finally, various CloudSat sampling issues are discussed in several appendices.

Igel, M. R.

van den Heever, S. C.

2018-08-10

Text

application/pdf

10.5194/acpd-15-15977-2015

https://acp.copernicus.org/preprints/acp-2015-271/

eISSN: 1680-7324

eng