ARL Weekly News – February 8, 2019

From 5-7 February, Temple Lee and Michael Buban participated in an intensive observation period of the Meso 18-19 field experiment, which is a continuation of the Verification of the Origins of Rotation in Tornadoes Experiment in the Southeast U.S. (VORTEX-SE) program. Meso 18-19, which started 1 November and runs through 30 April 2019, is focused on improving scientific understanding of severe weather genesis over the southeast U.S. To support this experiment, Temple and Michael launched soundings from Sikeston, Missouri, which was in a region where severe weather was most favorable in the Meso 18-19 domain.

Temple Lee attended the 99th annual American Meteorological Society conference in Phoenix, Arizona, and gave an oral presentation, with Michael Buban, Ed Dumas, and Bruce Baker listed as coauthors, on recent small unmanned aircraft systems (sUAS) work entitled “Toward Obtaining Daily Vertical Profiles of In-Situ Meteorological Measurements from Small Unmanned Aircraft Systems.” In the presentation, Temple summarized recent achievements with the sUAS work at ATDD, and he shared scientific results gleaned from ATDD’s sUAS observations that appeared in the group’s recently published paper in the journal Sensors.

The Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) wrote an article about its out of state researchers and featured Temple Lee in a recent edition. The full article can be viewed here.

ATDD has established a new collaboration with Brown University and the University of Rhode Island in support of a project to quantify wet and dry deposition of ammonium to Narragansett Bay, RI. The goal of the project is to improve understanding of non-point source nutrient loading to a coastal ecosystem. Multiple short-term field studies are scheduled for 2019. LaToya Myles, Mark Heuer, and Nebila Lichiheb will be involved with this effort.

The web page of the inline coupling of Weather Research and Forecasting model (WRF)-HYSPLIT has been updated ( A technical note 2019 was added to show the changes of inline HYSPLIT since the first release of the code in 2015. The latest release of the inline HYSPLIT coupled with WRF (version 3.7, 3.8.1, and 4.0.1) is now available for users to download. The major update of the inline HYSPLIT is to add three mixing schemes for estimating the turbulent velocity variance. In addition to the Kantha-Clayson method available in the previous releases, the updated version has the Beljaars-Holtslag method, the scheme to use the turbulent kinetic energy, and the option using the turbulent exchange coefficient.

Dennis Finn retired at the end of January. Since 2013, Dennis has been focusing on research related to FRD’s Project Sagebrush field studies. This work resulted in a number of highly regarded publications on dispersion and boundary-layer structure, particularly new insights into dispersion in the stable boundary layer. His retirement intentions were known well in advance, so FRD was able to organize a reasonable level of succession planning. Still, Dennis’s knowledge and contributions will be sorely missed. We wish him all the best in retirement.

Back in April 2018, FRD staff responded to an activation of the Emergency Operations Center at the Idaho National Laboratory (INL) resulting from the breaching of drums containing radioactive waste. Several high-volume air samplers located at FRD’s meteorological towers were activated for the event. Analysis of multiple observations—including the sampler filters at the FRD towers—indicated a spike above background radiation values around the time of the event. Although the spike was well below any safety thresholds, there still has been an investigation since the drums were in a building with functioning containment systems to prevent outside releases. At a meeting this week, it was revealed that the isotope mixtures on the analyzed filters do not match the contents of the drums. This has led to speculation that the observed spike may have resulted from another INL Site activity or perhaps natural variability that occurred around the same time as the event. For example, winds can sometimes raise dust containing fallout from long-ago atmospheric nuclear tests.