Modeling the dynamics of Pockets of Open Cells on Marine Stratocumulus: A complexity approach

More of Earth’s surface is covered by Stratocumulus clouds (Sc) than by any other cloud
type making them extremely important for Earth’s energy balance, mostly due to reflection of
solar radiation. However, representing Sc and their radiative impact is one of the largest chal-
lenges for global climate models because these cannot resolve the length scales of the processes
involve in its formation and evolution. For this reason, Sc clouds represent a large uncertainty
for climate projections [1].
The challenge becomes more intricate due to the organizational complexity that Sc clouds
present in a broad range of spatial scales. In particular, Sc fields over the oceans display
characteristic mesoscale patterns that can present both organized and unorganized structures.
Between these morphological types, cellular convection receives particular attention given than
cloud decks self-organize into honeycomb-like hexagonal patterns composed by closed and
open convective cells fields.
The purpose of this project is to model a particular tendency of Sc to organize into spatially
compact, cellular-patterned, low-reflectivity regions of open cells embedded in closed cellular
cloud fields called as pockets of open cells (POCs) [2].
First, an observational analysis of the time and spatial dynamics of POCs is made to under-
stand their creation, evolution and extinction. Then, using existing data of precipitation from
in-situ measurements on Sc clouds fields and Large eddy simulation (LES) models, a simplified
physical mechanism of the formation of POCs is proposed. Based on the previous results, an
heuristic model is developed using a statistical physics approach to capture the dynamics of
POCs and their relation with other atmospheric phenomena as cold pools and self-organized
convection.

[1] Wood, R., 2012: Stratocumulus Clouds. Mon. Wea. Rev., 140, 2373–2423,
https://doi.org/10.1175/MWR-D-11-00121.1https://doi.org/10.1175/MWR-D-11-00121.1.
[2] Stevens, B., G. Vali, K. Comstock, R. Wood, M. C. van Zanten, P. H. Austin, C. S. Brether-
ton, and D. H. Lenschow, 2005: POCKETS OF OPEN CELLS AND DRIZZLE IN MARINE
STRATOCUMULUS. Bull. Amer. Meteor. Soc., 86, 51–58, https://doi.org/10.1175/BAMS-86-1-
51https://doi.org/10.1175/BAMS-86-1-51.