ARL Weekly News – December 21, 2018

James Wood, Caleb Steele, Rick Lantrip, Wayne Bailey, and Walt Schalk supported a non-proliferation Source Physics Experiment on the Nevada National Security Site (NNSS). Support began months ahead of the experiment where detailed point forecasts and weather surveillance for the experiment location were provided. During the week of the experiment, the SORD team was in the field on location providing these detailed point forecasts and weather surveillance as well as participating in numerous experiment countdowns and practice scenarios. Due to the nature of the experiment, lightning/storm data/information and wind speeds (under 5 meters per second desired) were critical to the success of the experiment. A radiosonde balloon was released just after sunrise to help characterize the boundary layer environment and another balloon was released just after the experiment was executed and reached 7.25 millibars/98,212 feet. The forecast models were inconsistent leading up to the event; however, the weather on the day was good. The experiment was a success and a lot of good information was collected.

Walt Schalk has been working with a Department of Energy/National Nuclear Security Administration Laboratory Team to develop a plan to augment the current NNSS/SORD Mesonet to support an experiment beginning in 2021. The initial plan has the possibility to temporarily add to our current number of towers as well as tethersondes.

Caleb Steele has been running AERMOD (an atmospheric dispersion modeling system) with input from the NNSS to provide the modeling portion for the Nevada Air Permit.

Caleb Steele, our most recently hired meteorologist, will be going back over to the local National Weather Service office. Today is his last day at SORD. After the holidays, we will re-enter the hiring process.

As mentioned earlier in December, FRD obtained a 5 parts per million (ppm) gas calibration standard of the newer refrigerant HFO-1234ze to determine whether it has any utility as an atmospheric tracer. Samples of the chemical have been run through one of FRD’s gas chromatographs after reconfiguring the columns. The chromatograms based on electron capture detection do show a new wiggle that may be the signature of the refrigerant. However, this suspected response is so small at 5 ppm that the refrigerant would not be useful at the parts per trillion levels required for a tracer. There is still a possibility that the wiggle seen in the chromatograms is an unidentified contaminant chemical in the gas cylinder, whereas the refrigerant response is hidden by the pronounced oxygen peak. A new standard with the refrigerant mixed only with nitrogen has been ordered to test this possibility.

FRD’s web sites are now compliant with the https standard that encrypts connections to the sites. Since FRD’s internet access is provided by the Idaho National Laboratory (INL), the configuration changes required to support https were mainly performed by INL personnel.

A paper entitled “On the use of rotary-wing aircraft to sample near-surface thermodynamic fields: results from recent field campaigns,” by Temple R. Lee, Michael Buban, Edward Dumas, and Bruce Baker, was accepted for publication in the journal Sensors. In the paper, we discussed recent calibration and validation procedures for thermodynamic sensors used on two rotary-wing aircraft. We then used the measurements to characterize the spatiotemporal variability of near-surface temperature and moisture fields as a component of two recent field campaigns in which ATDD recently participated: the Verification of the Origins of Rotation in Tornadoes Experiment in the Southeast U.S. (VORTEX-SE) in northern Alabama and the Land Atmosphere Feedback Experiment (LAFE) in Oklahoma.