ARL Scientists Solve Operational Error in Nuclear Atmospheric Backtracking Capability

May 2018

In October 2017, a discrepancy in the number of stations in an automatic processing script caused Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operational failure; meaning that a routine process ended with an error message. Correcting the stated station number at NOAA’s National Centers for Environmental Prediction (NCEP) Central Operations (NCO) within 24-hours of discovery successfully solved the issue in the short-term, but since the package originally delivered to NCO included a checking function capable of identifying such errors in a request, ARL’s Barbara Stunder and Tianfeng Chai were enlisted to investigate how the error occurred. Stunder and Chai, along with colleagues at NCO, eventually discovered that the function hadn’t been fully implemented at NCO, so a help desk support​ ticket was submitted to implement a permanent fix. Development of an additional checking functionality in the operational software utilized by Senior Duty Meteorologists (SDMs) required a months-long collaborative effort between ARL, SDMs, NCO, and the NCEP Environmental Modeling Center. After multiple rounds of testing, full functionality was restored and proper operational response was verified. Successful resolution was declared in early May, and the ticket was officially closed.

CTBTO’s worldwide protection

Operated by the United Nations and the World Meteorological Organization (WMO), the CTBTO is tasked with monitoring the world in an attempt to stop all nuclear testing. An International Monitoring System comprised of 200 stations worldwide monitors underground, oceans, and the atmosphere for evidence of a nuclear explosion. Upon detection, an automated script issues instructions to the appropriate stations, which gather and report observational data within 24 hours.

NOAA, ARL provide vital contributions to national security interests

As an operational entity, NOAA serves as a resource to uphold the U.S. State Department’s agreement with the CTBTO; focused on identifying potential nuclear test source locations and determining the concentration of radionuclide material in the air. ARL scientists developed the software and website interface for an operational on-demand atmospheric backtracking capability implemented as part of the CTBTO-WMO Backtracking Response System in September 2014. ARL’s atmospheric transport and dispersion model, HYSPLIT, provides the capability to compute simulations of the backward trajectories, dispersion, and deposition (e.g. tracks the release to the source of its origin). The software is maintained by NCO and operated by SDMs within the National Weather Service, with ARL providing technical support when needed.