Meetings > PI / Science Team Meeting

Breakout Summary Report

 

ARM/ASR User and PI Meeting

10 - 13 June 2019

Interactions Among the Land Surface, Convective Boundary Layer, Clouds and Aerosols
10 June 2019
4:00 PM - 6:00 PM
50
Yunyan Zhang and Larry Berg

Breakout Description

The overarching theme for this breakout session was focused on land-PBL-cloud processes observed using ARM data and how these processes are represented in models ranging from LES to earth system models. There were 12 short presentations of ongoing research listed below. These include updates from recent LACI-related field campaigns such as CACTI, HI-SCALE, and LAFE and updates from different boundary-layer profiling instruments such as Raman lidar and Doppler lidar. There were general observational studies using ARM SGP and GoAmazon data and also model studies using LES, cloud-permitting models and large-scale climate models.

Main Discussion

List of Presentations:

  1. CACTI: LACI measurements (Adam Varble)

  2. Updates from HI-SCALE (Jerome Fast)

  3. Lidar update (Rob Newsom)

  4. Analysis of the shallow-to-deep convection transition using GoAmazon field campaign data (Yang Tian)

  5. Interactions between aerosols and PBL and implication for air quality (Zhanqing Li)

  6. The roles of large-scale advection and land surface conditions in the initiation of convection during HI-SCALE (Jingyi Chen)

  7. Land-atmosphere coupling strength for locally generated convective regimes at the ARM SGP site (Cheng Tao)

  8. Neglecting irrigation contributes to summertime warm-and-dry biases in climate model in the central US (Yun Qian)

  9. Differences in ECOR and EBBR turbulent flux measurements and their impacts on the large-scale forcing fields (Shuaiqi Tang)

  10. Characterizing vegetation spatial heterogeneity for cloud-resolving hindcasts in the SGP (Ian Williams)

  11. Surface observational data requirement from high-resolution modeling perspectives (Qi Tang)

  12. LAFE recent results (Volker Wulfmeyer)



We also had a general discussion. Topics included:




  • What data do we need to evaluate or constrain LACI processes in models?

  • In what ways can we increase collaboration?

  • Is ARM data adequate for your research need?

  • What contributes to modeling uncertainties related to LACI processes? How do we address them?

Key Findings


  • Adam Varble showed the current status of CACTI measurements and data and the classification of observed cloud regimes.

  • Rob Newsom showed ARM VAP data development updates for Raman lidar and Doppler lidar.

  • Based on a HI-SCALE LES case study, Jerome Fast showed that a model can reproduce observed heterogeneity in clouds and shallow-to-deep transitions only if realistic variations in soil moisture are used; Jingyi Chen showed that large-scale advection weakens the land forcing and delays precipitation.

  • Based on GoAmazon data, Yang Tian showed that local deep convection systems can be further categorized according to different triggering mechanisms, such as river-land breeze, cold pool driven, and morning initial condition disturbances.

  • Zhanqing Li showed Aerosol-PBL feedback plays a key role in modulating surface air quality, especially aerosol lowers PBL and makes less room to host pollutants.

  • Based on ARM SGP data, Cheng Tao showed differences in land-atmosphere coupling over different land covers for different local convective regimes and climate models show significant biases on surface energy budget even on clear-sky days.

  • Yun Qian used cloud-permitting simulations to show that irrigation increases surface evapotranspiration, and decreases surface temperature by increasing evaporative fraction. The increased precipitation alleviates part of the warm bias, likely by damping the positive feedback between soil moisture and temperature.

  • Shuaiqi Tand showed seasonal variation differences in surface fluxes measured by ECOR and EBBR and the impact on large-scale modeling forcing data development.

  • Qi Tang showed the heterogeneity in the relationship between EF, soil moisture, and leaf area index observed at extended facilities at the SGP site and how E3SM represents such relationship in the simulations with different horizontal resolutions.

  • Ian Williams showed a new algorithm to use ARM-observed LAI to help reclassify MODIS by vegetation types and how this would impact cloud permitting models' performance.

  • Volker Wulfmeyer showed LAFE observations help test and develop new relationships between variances, fluxes, and gradients and a nested model configuration for simulations down to turbulence-permitting scale available.

Issues

No new issues were identified.

Needs

To better characterize LACI processes in models, the group suggested:




  • Ensemble simulations should be carefully designed for initial conditions, large-scale boundary forcings, and for different model configurations, e.g., a combination of WRF PBL schemes testing.

  • High-resolution soil moisture, LAI, and soil texture data to address surface heterogeneity (Koichi specifically mentioned AI-based/deep learning methods might be useful to interpolate ARM observations and to process different variables (e.g., land cover, canopy height, rooting depth, soil moisture, soil temperature, etc.) with uncertainty estimates) (Volker also commented on the strong need of high-res land data input for LES simulations).

  • Both surface and boundary-profiling measurement over different land covers at SGP or near irrigated fields.



A following-up email discussion after the PI meeting (with inputs from Dave and Volker) agreed and suggested that VAP development should be more prioritized on the current products and made more operational (e.g., AERIoe and MWRRETv2) with better error estimates and add structure function and dissipation rate into the current doppler lidar “wstat” product.

Decisions

No specific decisions were made.

Future Plans

See Action items.

Action Items

Action items resulted from session (and subsequent follow-on discussion over the course of the meeting and email exchanges after the meeting):




  • A subgroup will be formed to investigate the development of a new PI product or VAP to determine the convective boundary-layer depth from the ARM Doppler lidars. The group felt that the systems and approaches are mature enough during convective conditions that the development of such a product should be relatively straightforward and would benefit the community.

  • A subgroup will be formed to investigate the possible collaboration to work on clear-sky boundary-layer development and turbulence structure. This is coming from discussions during the week of meeting after the breakout.

  • An AGU session was proposed and now is open for abstract submission. The topic is boundary-layer clouds and their interaction with the underlying surface.