2nd Workshop on Cloud Organization (WCO2)

Session

Poster pitches

16 May 2022, 12:00

Public Library (Utrecht)

21. In search of ghost cold pools and moisture rings

Adrian Tompkins (ICTP)

16/05/2022, 12:00

Poster

Moisture rings at cold pool fronts have been identified as playing a key role in convective propagation in numerical simulations. However, it is not clear if these are features of real cold pools due to the uncertainties of model microphysics and representation of turbulence at the cold pool front. We therefore analyse more than a decade of station observations from two islands in the tropical...

27. Understanding cloud systems structure and organization using a machine’s self-learning capability

Mr Dwaipayan Chatterjee (Institute for Geophysics and Meteorology, University of Cologne)

16/05/2022, 12:02

Poster

Our work aims to understand the structure and organization of cloud systems by exploiting the self-learning capability of a deep neural network. The neural network utilizes deep clustering and non-parametric instance-level discrimination for decision-making at any learning stage.

The data augmentation in the data pipeline, multi-clustering of the dense vectors, and Multilayer perceptron...

59. Self-organized quantization and oscillations on continuous fixed-energy sandpiles

Jan Haerter (Niels Bohr Institute, Copenhagen University)

16/05/2022, 12:04

Poster

Atmospheric self-organization and activator-inhibitor dynamics in biology provide examples of checkerboard-like spatio-temporal organization. We study a simple model for local activation-inhibition processes. Our model, first introduced in the context of atmospheric moisture dynamics, is a continuous-energy and non-Abelian version of the fixed-energy sandpile model. Each...

58. Network approaches to the geometric structure of shallow cloud fields

Franziska Glassmeier (TU Delft)

16/05/2022, 12:06

Poster

The cellular structure of stratocumulus clouds decks and their evolution has been modeled by describing them as cellular, nearest-neighbor networks (Glassmeier& Feingold, 2017, PNAS). We review this approach and discuss options and challenges for its generalization to shallow cumulus cloud fields.

9. How well do stereo cameras observe shallow cumulus spatial organization? An evaluation combining atmospheric path-tracing and high-resolution Large-Eddy Simulations (LES)

Yannick Burchart

16/05/2022, 12:08

Poster

Spatial organization is essential for convection parameterization in numerical weather and climate models. However, spatial organization is challenging to observe. Most ground-based measurements consist of one-dimensional profile data, often sampled by lidars or radars. A recently explored new method of obtaining multi-dimensional information is to utilize hemispheric images from networks with...

13. Diurnal signals in flower cloud organization in the upstream Tradewind regions during EUREC4A

Salima Ghazayel (University of Cologne)

16/05/2022, 12:10

Poster

Tradewind shallow cumulus clouds cover vast areas of the subtropical oceans, and are associated with various modes of mesoscale organization. During the EUREC4A field campaign in the subtropical Atlantic in early 2020, unique in-situ and remote sensing measurements were made that allow characterization of Trade wind cloud organization as well as the large-scale environment in which this...

60. The spacing and thermodynamics of updraughts in organised shallow cumulus

Steven Boeing (University of Leeds)

16/05/2022, 12:12

Mesoscale organization of shallow and deep cumulus convection

Poster

We consider the clouds that form in Lagrangian high-resolution and single-column model simulations based on different days of the EUREC4A/ATOMIC field campaign. These simulations are driven using ERA5 reanalysis, and contain examples of flower type and gravel type organisation. In particular, we consider the spacing and thermodynamic properties of updraughts and detrained air during different...

52. Dependence of Cloud Radiative Effect on Cloud Organization in the Trades

Pouriya Alinaghi (TU Delft), Franziska Glassmeier (TU Delft)

16/05/2022, 12:14

Poster

Shallow cumuli are the most frequent types of clouds over the subtropical oceans where they occur in several shapes and patterns. These types of clouds potentially play a major role in regulating the radiative budget of the Earth system. An important question is to what extent cloud patterns alter under climate change and how this will feedback onto a rising of temperature. In this study, we...

14. Clear-Sky Turbulence and Shallow Convection: New Insights Combining SAR Images, Satellite Brightness Temperature and In-Situ Measurements

Pierre-Etienne Brilouet

16/05/2022, 12:16

Poster

Studying the marine atmospheric boundary layer (MABL) processes at play to organize cloudiness through satellite products is challenging. Here, we propose an innovative approach to investigate the MABL dynamical structures by combining spaceborne Synthetic Aperture Radar (SAR) images, and brightness temperature measurements from the Geostationary Operational Environmental Satellite...

16. Cloud size and cloud spacing distributions of trade-wind cumuli observed at cloud base for a range of mesoscale organizations

Julius Mex (LMD)

16/05/2022, 12:18

Poster

During the EUREC4A field campaign that took place near Barbados in Jan-Feb 2020, the French ATR aircraft flew in the lower troposphere and characterized the macrophysical, microphysical and turbulent properties of trade cumuli around the cloud-base level. Using horizontal lidar-radar observations and in-situ measurements, we characterize the cloud size and cloud spacing distributions of cumuli...

63. Momentum transport and the organization of shallow convection

Alessandro Carlo Maria Savazzi (Delft University of Technology)

16/05/2022, 12:20

Poster

Simulations of a marine cold air outbreak with the mesoscale weather model HARMONIE suggest that parameterized shallow convective momentum transport acts to diminish circulations that accompany cellular cloud structures. In this study we test this hypothesis in the trade-wind region where various type of shallow cumulus cloud patterns occur using a hierarchy of model simulations of the EUREC4A...

43. Shallow convective organization in the Trades as seen by self-learning artificial intelligence

Sabrina Schnitt (University of Cologne)

16/05/2022, 12:22

Poster

The organization of shallow convection in the trades influences precipitation development, cold pool formation, clouds’ radiative effects, and, thus, climate sensitivity. Deep learning techniques, especially in computer vision and self-supervision, are suitable tools to understand cloud organization purely from a machine’s perspective. Yet, the physical interpretation of the network’s classes...

82. A new conceptual picture of the transition layer

Anna Lea Albright

16/05/2022, 12:24

Poster

In the trades, the transition layer above the mixed layer top has long been observed and simulated. Yet its origins remain little investigated. The transition layer is often associated with an about 150 m deep layer between the mixed and subcloud layer tops that acts as a barrier to overlying convection. Using extensive observations from the EUREC4A field campaign, we propose a new conceptual...

75. Process Oriented evaluation of the oversea AROME configuration: focus on the representation of cloud organisation

Florent Beucher (Météo-France)

16/05/2022, 12:26

Poster

This study evaluates the ability of the French Convection-Permitting model AROME-OM to represent shallow cumulus and their main organisations for boreal winter conditions in the North Atlantic trades.
It uses a set of three winter seasons (January-February 2018-2020) of high-resolution (1.3 and 2.5 km) simulations over the Caribbean domain (9.7-22.9°N, 75.3°W-51.7°W).
The model is assessed...

67. Competition between convection of mesoscale patterns and its impacts on self-organization in idealized CRM simulations

Wei-Ming Tsai (University of Miami)

16/05/2022, 12:28

Poster

This study first aims to address why mesoscale convective patterns are important and investigate the effects on both dynamics and thermodynamics using a cyclic cloud-permitting model, CM1. A set of idealized experiments to address the competition between isolated and agglomerated, organized convection using large-domain simulations with explicit representations of both convective-scale and...

69. Factors controlling precipitation in idealised monsoon simulations over an aquapatch

Maxime Colin (Leibniz Centre for Tropical Marine Research)

16/05/2022, 12:30

Poster

The traditional view of monsoons as continental sea breezes generated by land-sea contrasts was shown to have serious limitations. Therefore, it remains unclear if the surface temperature contrast matters for the monsoon precipitation, and why there is a non-linear intensification of precipitation intensity with surface temperature forcing. Here, we aim to determine if monsoon non-linearities...

22. The Diurnal Evolution of Controls on Trade Wind Mesoscale Morphologies

Paquita Zuidema (University of Miami, RSMAS, USA)

16/05/2022, 12:32

Poster

The diurnal cycle in trade-wind cloudiness is thought to be driven by the diurnal cycle in the relative occurrence frequency of mesoscale cloud morphologies (i.e., Vial et al. 2021). These morphologies can be grouped by their distinct appearance and size into four categories: Sugar, Gravel, Flowers, and Fish. The diurnal cycle in cloudiness is associated with a late afternoon maximum in the...