Numerical simulation of observed submesoscale plume meandering under nocturnal drainage flow

• Published in: Atmospheric environment (1994) 2013-04, Vol.69, p.29-36
• Main Authors: Sandeepan, B.S., Rakesh, P.T., Venkatesan, R.
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric pollution; Dispersion modeling; Exact sciences and technology; FLEXPART-WRF; Meandering; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Submesoscale; WRF
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2012.12.007

Bimodal plume shapes are occasionally observed in the series of tracer release experiments conducted at Hanford known as Hanford 67. These particular cases have not been studied so far. A possible reason for the bimodal shape could be the nocturnal submesoscale meandering of wind over the valley terrain. This study investigates the ability of state of art nested numerical model (WRF-ARW) to dynamically down scale up to submesoscale range (10 km in space and less than one hour in time) to simulate the meandering wind flow. The simulated wind field is used to drive a Lagrangian particle dispersion model, FLEXPART-WRF for plume simulation. From the study it is confirmed that the reason for this bimodal plume pattern is the wind meandering with periodicity of the order of ∼30 min having physical origin in the nocturnal drainage flow. Further, it is observed that the above submesoscale motion could be simulated using WRF model by reducing the grid size to 1 km in the horizontal plane. ► Simulation of submesoscale wind meandering under drainage flow using WRF model. ► Analysis of Hanford, 1967 tracer release experiment data. ► Simulation of observed bimodal plume pattern using FLEXPART-WRF.