Breakout Summary Report

ARM/ASR User and PI Meeting

2 - 6 May 2016

Session Title: Land-Atmosphere-Cloud Interactions (LACI)
Session Date: 5 May 2016
Session Time: 10:45 AM - 12:45 PM
Number of Attendees: 0
Summary Authors: Larry Berg, Ian Williams, Margaret Torn, Dave Turner, Yunyan Zhang

Breakout Description

The LACI breakout session provides the opportunity for interested member or the ARM/ASR science community to present recent findings, discuss data needs, and explore opportunities for collaboration.

Main Discussion

The breakout session was broken into two main components, one focused on science questions associated with the Southern Great Plains (SGP) site and the other focused on questions relevant for the North Slope of Alaska (NSA) site. Each section included a detailed science discussion that was followed by a short question-and-answer period. Yunyan Zhang provided an updated of her Early Career Award research that focused on linking convective clouds to the soil moisture at the SGP. The second science talk was provided by Peter Thornton. This talk dealt with radiation measurements at the NSA and explored additional linkages between ARM/ASR and NGEE Arctic research communities. These talks were augmented by a number of short “flash talks” that were designed to generate additional discussion and highlight the growing amount of LACI-related work within ASR. These short presentations are summarized in the table below.


SGP
Heng Xiao: Nested WRF LES of the clouds over the SGP
Joe Santanello: Update on GEWEX Local-Coupling (LoCO) project
Alex Laskin: New findings related to the generation of aerosol from the impact of rain drops on bare soil
Amir Naqw: New measurements of aerosol chemical composition
Shaocheng Xie: Update on relevant measurements and data products at the SGP
David Cook: Update on soil moisture measurements at the SGP
Lara Kueppers: Introduction to potential field deployment related to NGREE Tropics
Alice Cialella: Update on new land-use/land-cover data products for the area around the SGP (effort being tracked via ServiceNow-1265 Task)
Neil Lareau: Sub-cloud turbulence structure from Doppler Lidar observation

NSA
Matt Shupe: Interactions between clouds and surface properties at the NSA
Sebastien Biraud: Initial measurements of surface albedo over the NSA measured during ACME-V

Issues

Following the invited presentations and flash talks, the discussion highlighted several issues:
• ARM and ASR have recognized that spatial and seasonal variability are important, but questions remain on how to upscale information to the large scale. There is a need within ASR to develop a strategy to better address these issues.
• BERAC has suggested that DOE extend the NGEE Tropics measurements to altitudes above the treetop, and ARM/ASR could be a key collaborator in this work.
• There remain issues in regards to the closure of the surface energy budget measured using the ECOR systems and questions on using the co-located SEBS data with ECOR. Shaocheng proposed data assimilation approaches using an offline land model to close the energy budget.

Needs

Data needs were also a topic of discussion. It was pointed out that the deployment of the new soil moisture sensors is a significant step forward, which addresses one of the most pressing needs that had been identified by the group. Some attendees suggested the need for hyperspectral measurements to infer more about the ecosystems around the SGP. It is possible that these measurements could be added to a UAV deployed at the NSA. Another measurement that should be considered is near-surface CO2 or CO2 fluxes at the new boundary facilities. These measurements could be used to evaluate retrievals and for the validation of large-scale models. Such measurements would augment those made on the Cessna or with remote-sensing instruments.

Future Plans

The group recognized the utility of LASSO, which has been focused on the SGP. ARM’s Decadal Vision indicates that the NSA would be the next target, but questions remain in regard to how to treat the surface variability (in both space and time), and the lack of high-quality data that could be used to develop the required forcing data set. It would be helpful for the LACI team to provide input to ARM in this area.
The group also discussed actions related to the BERAC suggestion that NGEE Tropics be extended to include an atmospheric component. There was some support among the group and a sub-group will start to explore options related to such a deployment. It was also suggested the GoAmazon be used, as applicable, as a way to jump-start this line of research. It was pointed out that during the design of GoAmazon there was not close collaboration between teams working to understand processes in the soil and canopy and the atmosphere. The first step in this process is to carefully define science questions that could form the basis of a proposal.

Action Items

Action items from the meeting include:
• Development of an ad hoc team to explore potential for ARM/ASR involvement in NGEE Tropics. The group will initially consist of Lara Kueppers and Margaret Torn (LBNL), and Samson Hagos and Larry Berg (PNNL), but should be expanded to include additional scientists.
• After additional consultation with DOE program managers, the LACI group should finalize the existing draft LACI white paper and explore other options for providing additional information to DOE, which could include a formal workshop.