BIRDIE

 

Beryllium Isotopes in Rainfall for STE Dynamics Ex

1 May 2022 - 30 June 2022

Lead Scientist: Sonia Wharton

Observatory: sgp

BIRDIE is a precipitation collection experiment designed to measure cosmogenic isotopes of beryllium, 7Be (half-life = 53 days) and 10Be (half-life = 1.4 million years), in rainfall and other forms of precipitation across the U.S. Department of Energy Southern Great Plains (SGP) ARM site. We will use more than 15 SGP ARM sites across southern Kansas and northern Oklahoma in early summer to capture spatial and temporal variability in 10Be/7Be for purposes of elucidating troposphere-stratosphere exchange (STE) dynamics, with a focus on identifying strong deep convection activity (i.e., intrusions of water vapor into the stratosphere caused by overshooting). Beryllium isotopes are not measured in real time: instead, water samples are brought back to Lawrence Livermore National Laboratory (LLNL)’s Center for Accelerated Mass Spectrometry (CAMS). While rainfall collections of 7Be are not new, large spatial data sets for event-scale investigation have been unfeasible until recently; furthermore we do not know of any comprehensive studies that have looked at 10Be/7Be in precipitation samples. We hypothesize that 10Be/7Be can be used to infer information about the strength and extent of convection processes because production rates of 7Be and 10Be differ strongly with altitude. BIRDIE will take place during NASA’s Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) experiment (https://dcotss.org/) centered at Salina, Kansas. During DCOTSS the LLNL team will also collect 10Be/7Be in the stratosphere over Kansas using high-altitude balloons. Those airborne ratios will be compared to the precipitation ratios measured during BIRDIE to evaluate whether ground-based measurements can provide information about STE dynamics. Data available include precipitation event day and duration, event precipitation amount, rain rate (where available), and concentrations of 10Be and 7Be in the event sample. 

Co-Investigators

Alan Hidy
Marisa Repasch

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