ARL Weekly News – February 18, 2022

Upcoming Events

Source Attribution Challenge Begins in Oak Ridge.

The Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL) developed a next generation Xenon detector with engineering and production transferred to Teledyne Brown Engineering, Knoxville, TN. In 2020, during testing and evaluation of the next Xenon International measurement system, the Teledyne facility located in Hardin Valley, Knoxville, TN detected multiple isotopes of Xenon – of particular relevance was the detection of 125Xe, 127Xe, and 129mXe. Nuclear specialists have attributed the presence of 125Xe to only one source, DOE’s Spallation Neutron Source (SNS) located on the DOE’s Oak Ridge Reservation. A conference proceeding describing the measurement system and sample analysis can be viewed at

Of particular relevance to ARL is the direct attribution of measured 125Xe concentration to a specific source. In this case there can only be one source, 125Xe emitted from the SNS exhaust stack. This event provides an unique opportunity to examine uncertainty in ARL’s HYSPLIT transport and dispersion within complex terrain using various operational as well as experimental numerical weather prediction models as drivers for the HYSPLIT transport and dispersion process. Ongoing discussions with SNS and PNNL personnel, have identified the primary need to quantify the half-life for 125Xe to accurately predict travel times as an initial step.

Recent Events

Climate Science Education Talks for Middle School Students
Dr. Howard Diamond made a series of four half-hour virtual talks on climate change science and his work career as a climate scientist at NOAA to approximately 300 8th grade students at Old Mill Middle School South in Millersville, MD in Anne Arundel County Maryland on February 18th. He initially made this series of talks in April 2021, and was invited back this year by the school’s STEM Coordinator. The students were studying the effects of the El Niño Southern Oscillation and its effect on weather and climate and so Dr. Diamond made that topic a particular emphasis in this year’s talks. The students appeared interested and had some good questions to pose.


Snow Measurement Paper Published

How Well are We Measuring Snow Post-SPICE? was published in the Bulletin of the American Meteorological Society. Led by John Kochendorfer and co-authored by ARL authors Bruce Baker (retired) and Tilden Meyers, the article provides a broad overview of automated snow measurement research from the last 10 years. It includes a summary of significant results from the World Meteorological Organization’s Solid Precipitation Intercomparison Experiment (WMO-SPICE) and more recent publications.