Breakout Summary Report

ARM/ASR User and PI Meeting

Session Title: Interactions among the land surface, convective boundary layer, clouds and aerosols
Session Date: 24 June 2021
Session Time: 11:00 AM - 1:00 PM
Number of Attendees: 50
Summary Authors: Larry Berg and Yunyan Zhang

Breakout Description

This breakout session aims to:
1) Use ARM data and high-res models as tools to improve our understanding of the impact of land surface on boundary-layer turbulence and cloud dynamics/morphology.
2) Diagnose model biases on the interface between atmosphere and land surface.
3) Improve model parameterization in representing the interaction and feedbacks between land surface, convective boundary layer, clouds, and aerosols.

The overarching theme for this breakout session was focused on land-PBL-cloud processes observed by ARM data and how these processes are represented in models. This breakout focused on process studies at local and diurnal scales and included:
1)Results from long-term SGP data analysis, LES/cloud- permitting model studies, and regional and climate model simulations.
2) Updates on ARM land surface/boundary-layer profiling measurements and data development.
3)Updates and results from recent and upcoming field campaigns.
4)Updates from the recent AmeriFlux workshop co-sponsored by ARM/ASR – “Improving understanding of land atmosphere interactions through integration of surface flux and atmospheric boundary layer."

The recorded session is available here.

Main Discussion

Specifically, this breakout included a range of scientific talks, updates associated with field studies, and discussion among the attendees.

Three AGU-style talks:
1.Effects of Surface Energy Partitioning on Convective Organization: An observational and modeling case study in the US Southern Great Plain. (Yi Dai)
2.Determining Spatial Scales of Soil Moisture – Cloud Coupling Pathways using Semi-Idealized Simulations (Koichi Sakaguchi)
3.Improved Understanding of Land-Atmosphere Interactions Using Observations and Models (Dave Turner)

Six lightning talks:
The lightning talks were selected to highlight posters in the session after the breakout.
1.An overview of irrigation impact on land–atmosphere-cloud interactions (Yun Qian).
2.Observational evidence of the land cover effect on shallow cumulus clouds over the U.S. Southern Great Plains (Jingjing Tian).
3.Observational and modeling studies of cloud-surface decoupling over land and ocean (Youtong Zheng).
4.Warm-season PBL evolutions from lidar observations, LASSO, and single-column model simulations at the SGP site (Zhien Wang).
5.A decentralized approach in modeling organized convection and its impacts on continental boundary layers at SGP (Roel Neggers).
6.Using ARM data to evaluate convection-permitting simulations on the summertime surface climate over the central United States (Hongchen Qin).

Five short updates from workshops or field campaigns:
1.AmeriFlux Workshop on land-atmosphere interaction (Manuel Helbig).
2.Lidar and PBL profiling instruments (Rob Newsom).
3.SAIL (Dan Feldman).
4.TRACER (Virendra Ghate and Mike Jensen).
5.SEUS (Chongai Kuang).

A short discussion on:
Planetary boundary-layer profiling layout and setting around the SGP and SEUS sites,

Key Findings

Due to the text limit of this section form, for the key points on the talks and updates, please view the full breakout summary report here .

Due to the time limitation of this breakout, we were not able to accommodate questions after each talk, however active discussions were carried on by zoom chat, breakout slack channel, and also at individual poster slack channels. The breakout slack channel was particularly helpful to maintain the momentum during and after the breakout by threading and so on.

We had about 15 to 20 minutes discussion towards the end of the session. It was dedicated to “PBL profiling layout and setting at SGP and SEUS sites and other upcoming field campaigns.”

Particularly this group feedback to SEUS AMF and actively discussed with Chongai Kuang including:
1) The potential triangle setting of AERI for the benefits of cloud LWP retrievals and the characterization of advection of water vapor and temperature
2) The flux measurement at the interface of canopies
3) The partitioning between soil and plant evapotranspiration
4) The main site and extend sites to represent land cover heterogeneity
5) The potential contribution from AmeriFlux program on flux measurement

Dan Feldman also commented on the scanning doppler lidar capability during the SAIL campaign and potential measurements on the flow along the slope.

Issues

N/A

Needs

N/A

Decisions

N/A

Future Plans

N/A

Action Items

Two AGU sessions have been proposed and associated with this focus group:
•“H068 - Land-Atmosphere Interactions: From Bedrock to Boundary Layer”
•"B042 - Improving Understanding of Land-Atmosphere Interactions through Integration of Surface Layer, Atmospheric Composition, and Atmospheric Boundary Layer Measurements"