Meetings > PI / Science Team Meeting

Breakout Summary Report

 

ARM/ASR User and PI Meeting

10 - 13 June 2019

Evaluation of Measurement Needs to Address Cloud and Precipitation Science Issues
12 June 2019
1:30 PM - 3:30 PM
75
Jim Mather and Ann Fridlind

Breakout Description

The Clouds and Precipitation Measurements and Science Group (CPMSG) was formed in April 2019 and brings together cloud and precipitation scientists and ARM staff to facilitate communication between ARM and the science community on the topic of improving the application of ARM measurements to cloud and precipitation science. This session was organized to provide an update on ARM cloud and precipitation measurements and then conduct a public discussion, begun in the CPMSG, to review both what measurements are working well and where there are measurement or data product gaps across a set of science themes of interest to ASR.

Main Discussion

Jim Mather first presented an update on ARM cloud and precipitation measurements:

  • Status of the ARM radars, first look at the FY20 radar plan (emphasis on Arctic and preparations for TRACER)

  • Status of radar data products and products for potential development

  • Plans to refresh RWPs at SGP and NSA. Consider 449 MHz for Utqiagvik

  • Overview of bulk frozen precipitation at Barrow and Oliktok.

  • Planned upgrade for Utqiagvik HSRL

  • Considering refresh of MPL network; summary of lidar survey

  • In process of refreshing MWR3C network

  • Will likely soon need to replace TSI network



Ann Fridlind (the chair of the CPMSG) led the group through a discussion of six thematic areas highlighting ARM strengths in each area, identifying gaps, and soliciting additional input on these areas. The six thematic areas were put forward by the CPMSG during its first virtual meeting in April. The six thematic areas and input received from the group during Ann’s presentation is summarized here:




  1. Boundary-layer structure and near-cloud dynamics


    • Valuable to observe 3D sub-cloud structure (e.g., w/Doppler lidar)



  2. Shallow-warm cloud precipitation formation and structure


    • Again, 3D structure important ( scanning); benefit from more than one radar frequency

    • Calibrated ceilometers could provide information about precipitation

    • Aerosol profiles also important



  3. Hydrometeor phase evaluation in climate models


    • Discussion of importance of instrument simulators

    • Valuable to have open-source code to combine measurements (e.g., radar/lidar)

    • Need uncertainties



  4. Ice properties and processes


    • Need more in situ observations (mass size distribution would be useful at surface)

    • Retrievals should identify more than one habit (for comparison with models)

    • Need scanning strategies that serve community needs



  5. Coupled dynamics and microphysics in deep convections


    • Consideration of special scan operations (radar and lidar) along with baseline

    • Need 3D thermodynamic structure and vertical profiles of aerosols; satellite also useful

    • Benefit from multiple disdrometers (one baseline and others for statistical sampling)

    • Need to implement certain data sets so more scientists can engage. Would be useful to get a short period for exploration.

    • Is there a place for lab studies? Potentially through ASR or EMSL



  6. Cirrus dynamics and microphysics


    • (no discussion on this point)




Breakout attendees were asked if there were any topics that had been overlooked and there were two responses:




  • Mixed-phase cloud processes (which could fit under an expanded version of hydrometeor phase evaluation)

  • Cloud organization



And finally, miscellaneous input at the end of the session included the following suggestions:




  • We would benefit from ocean properties at ENA (the Azores does operate a few buoys but they are primarily for wave state)

  • We would benefit from vertical profiles of cloud condensation nuclei

  • We are not currently collecting spectra from the Doppler lidar. If we did, that would provide useful information for precipitation retrievals


Future Plans

This breakout was an information-gathering session. The next steps are to assimilate this input, bring together the CPMSG, and begin to look at the issues raised with the expectation of developing strategies to address the needs raised. The CPMSG also intends to develop a survey to solicit additional input regarding what measurements and data products are effectively meeting community science needs and where there are gaps. Once this additional input has been obtained, the plan is to organize a workshop to work on the issue of how to best apply ARM resources to advance these science themes.