Breakout Summary Report
ARM/ASR User and PI Meeting
2 - 6 May 2016
4 May 2016
7:30 PM - 9:00 PM
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Rob Newsom and John Goldsmith
Breakout Description
The goal of this session was to provide a forum for instrument mentors to communicate current instrument status, and to allow any interested members of the science community to describe how lidar data are being used. The meeting focused exclusively on the Doppler, Raman, and High Spectral Resolution lidar systems.Main Discussion
The meeting agenda was as follows:• Doppler lidar instrument update and Doppler lidar VAPs by Rob Newsom
• Raman lidar VAP update by Rob Newsom
• Raman lidar instrument update by John Goldsmith
• HSRL instrument Update by Ed Eloranta
• “Using Raman lidar to diagnose RHcrit” by Kwiten Van Weverberg
• CHARMS update by Tyler Thorsen
Rob Newsom presented a brief overview of the ARM Doppler lidars, their current operational status, and the new VAPs that have come online in the last year. A good part of this presentation focused on the recent procurement of three new Doppler lidar systems, and the deployment of these systems at the SGP boundary and central facilities. There was a brief discussion of how best to configure and run (i.e., scan strategies) these systems to support the high-resolution modeling efforts.
Rob also provided a brief status update on the Raman lidar (RL) VAPs. Currently, the VAPs are not being run operationally as we transition to upgraded versions of the VAPs running within the ADI frame work. Efforts are currently underway to integrate the Raman lidar VAPs into the ADI, starting with the so-called MERGE VAP that forms the starting point for all the other RL VAPs. The current plan is to move forward with the integration of the mixing ratio and temperature VAPs into ADI, and to replace the existing aerosol VAPs with Tyler Thorsen’s FEX code.
John Goldsmith provided a brief overview of the ARM Raman lidars and their current operational status, including the SGP, ENA and Oliktok systems. In the past year, the system that was previously deployed at Darwin was successfully installed on Graciosa, and the SGP system has been upgraded and moved to the Radar cluster at the central facility. Part of the SGP RL upgrade involved installation of a much improved HVAC system that has dramatically reduced thermal cycling issues. The SGP system now exhibits the same degree of thermal stability as the ENA and AMF3 systems.
Laser issues continue to plague the Oliktok (AMF3) system. After several failed attempts to repair the laser at the site, the system was shipped to the vendor for repair. It has now been repaired and will be shipped back to Oliktok and reinstalled in the near future.
Ed Eloranta provided an overview of the ARM HSRLs and their current operational status. Overall, Ed reported that the ARM HSRLs have been and are currently running well. A good part of Ed’s presentation focused on calibration issues associated with the 1064 nm channel (non-ARM system) and impacts on CHARMs results.
Following the instrument and VAP updates, we had two presentations on the applications of the Raman and HSRL data. Kwiten Van Weverberg (UK Met Office) presented work that he has been doing on the use of RL temperature measurements to diagnose RHcrit, with an emphasis on how lidar performance issues impacted the analysis. One issue that presented a challenge was the thermal cycling artifacts that plagued the SGP RL prior to the recent upgrade. It was suggested that Kwiten consider running his analysis using data after the recent upgrade and/or using data from the Darwin/Azores system to determine if this results in any improvement.
Tyler Thorsen presented an update on the CHARMS (3-beta+2-alpha) field campaign. The discussion here was mostly geared toward data-processing methodologies. In order to combine backscatter and extinction measurements from the HSRL and the Raman lidar, it was necessary to apply common processing methodologies to both raw data streams. Tyler described the adaptive filtering and QC techniques that were used to process the CHARMS data (i.e., the same techniques used in Tyler’s FEX RL code). Again, one issue that presented a challenge was the thermal cycling artifacts that plagued the SGP RL prior to the recent upgrade.
Future Plans
Given the recent improvements in the performance of the SGP RL and the improvements in the 1064nm calibration methodology for the HSRL, the suggestion was made that we consider a second deployment of the University of Wisconsin HSRL to the SGP RL at some point in the not-too-distant future.Action Items
• Get the RL MERGE, water vapor mixing ratio (MR), and temperature VAPs operational within the ADI frame work.• Replace existing RL aerosol VAPs (i.e., ASR, EXT and DEP) with Thorsen’s (Matlab) FEX code. Work with DMF to overcome challenges associated with running Matlab code operationally. Explore the possibility of integrating the FEX code into ADI.
• Get the Oliktok Raman and AMF1 Doppler lidars operational again.