Robert L. Buckley

An Observational and Numerical Study of the Nocturnal Sea Breeze. Part I: Structure and Circulation

Abstract Characteristics of inland-penetrating nocturnal sea breezes at the Savannah River Site (SRS) in South Carolina are discussed. Detailed observations from an area tower network during the Stable Boundary Layer Experiment (STABLE) indicate passage of marine air through SRS on three different nights. Large-scale winds are directed onshore for the first two nights, resulting in similar boundary layer structure and stability on these nights, while synoptic winds on the third night are offshore, leading to stronger convergence and wedging of the marine air under the inland air mass. The Regional Atmospheric Modeling System (RAMS) is used to simulate conditions for the final two nights. General features of the sea breeze are captured by the model, including wind shifts, moisture increases, turbulence structure differences between the two nights, and the formation of Kelvin–Helmholtz billows along the interface of marine and return airflow.

Modeling Dispersion from Toxic Gas Released After a Train Collision in Graniteville, SC

Abstract The Savannah River National Laboratory (SRNL) Weather Information and Display System was used to provide meteorological and atmospheric modeling/consequence assessment support to state and local agencies after the collision of two Norfolk Southern freight trains on the morning of January 6, 2005. This collision resulted in the release of several toxic chemicals to the environment, including chlorine. The dense and highly toxic cloud of chlorine gas that formed in the vicinity of the accident was responsible for 9 fatalities and caused injuries to more than 500 others. Transport model results depicting the forecast path of the ongoing release were made available to emergency managers in the county’s Unified Command Center shortly after SRNL received a request for assistance. Support continued over the ensuing 2 days of the active response. The SRNL also provided weather briefings and transport/consequence assessment model results to responders from the South Carolina Department of Health and Environmental Control, the Savannah River Site (SRS) Emergency Operations Center, Department of Energy headquarters, and hazard material teams dispatched from the SRS. Operational model-generated forecast winds used in consequence assessments conducted during the incident were provided at 2-km horizontal grid spacing during the accident response. High-resolution Regional Atmospheric Modeling System (RAMS, version 4.3.0) simulation was later performed to examine potential influences of local topography on plume migration in greater detail. The detailed RAMS simulation was used to determine meteorology using multiple grids with an innermost grid spacing of 125 m. Results from the two simulations are shown to generally agree with meteorological observations at the time; consequently, local topography did not significantly affect wind in the area. Use of a dense gas dispersion model to simulate localized plume behavior using the higher-resolution winds indicated agreement with fatalities in the immediate area and visible damage to vegetation.

An Observational and Numerical Study of the Nocturnal Sea Breeze. Part II: Chemical Transport

Abstract Chemical transport at the Savannah River Site (SRS) in South Carolina during nocturnal sea-breeze passage is examined using simulations from a three-dimensional mesoscale dynamic model [(RAMS) Regional Atmospheric Modeling System] and a Lagrangian particle dispersion model (LPDM) and supplemental surface measurements of sulfur hexafluoride (SF6) obtained during a 1988 field campaign. Plume dispersion and regional transport were characterized by nights with onshore and offshore synoptic winds. For onshore winds, the sea breeze lifts, redirects, and broadens an initially narrow plume but maintains its general structure. Regional calculations reveal particle translations exceeding 100 km under these conditions. On the other hand, with offshore synoptic winds, frontal passage leads to stronger lifting, turbulence, and vertical shearing that fragments the plume. In addition, complicated recirculation of pollutants is possible and may increase chemical concentrations in areas near the source. Observed ...

Ensemble Modeling of Air Pollution Due to April 2010 Island Volcano Eruption

The eruption of Island volcano in April 2010 caused enormously big troubles for air transport over Europe for a long period of time. The losses and inconveniences for air companies, common business and usual passengers are difficult to be estimated but in any case are rather considerable. The insights from this extraordinary event are that serious efforts must be put in studding not only the volcanic events but in creating tools for reliable forecast of volcano products (mainly ash) distribution in case of eruption. There are few centers devoted to observation and forecast of such events. Some meteorological services lately created respective systems. The ENSEMBLE consortium leaded by European JRC in Ispra, Italy, which is aimed at elaborating ensemble forecast on the base of individual forecasts of almost all European Early Warning Systems (EWS) in case of nuclear accident decided to launch a series of exercises devoted to simulation of the first week air pollution dilution caused by Island volcano eruption. Bulgarian ERS (BERS) was upgraded as to be able to take part in these exercises and its results and comparisons with other model results are the object of this work.

Savannah River National Laboratory Emergency Response Capability for Atmospheric Contaminant Releases

ABSTRACT Emergency response to an atmospheric release of chemical or radiological contamination is enhanced when plume predictions, field measurements, and real-time weather information are integrated into a geospatial framework. The Weather Information and Display (WIND) System at Savannah River National Laboratory (SRNL) utilizes such an integrated framework. The rapid availability of predictions from a suite of atmospheric transport models within this geospatial framework has proven to be of great value to decision makers during an emergency involving an atmospheric contaminant release.